Dormant to active appurtenances for reporting information regarding wound dressings

ABSTRACT

Appurtenances to wound dressings can include: a substrate configured to attach to a wound dressing; a fluid-activated voltaic cell attached to the substrate; a transmission unit attached to a surface of the substrate, the transmission unit including circuitry and at least one antenna, the transmission unit configured to transmit a signal in response to current generated by the fluid-activated voltaic cell; and a projection operably attached to the fluid-activated voltaic cell, the projection of a size and shape to extend into an interior region of the wound dressing and configured to sample a fluid within the interior region of the wound dressing.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application is related to and claims the benefit of theearliest available effective filing date(s) from the following listedapplication(s) (the “Related Applications”) (e.g., claims earliestavailable priority dates for other than provisional patent applicationsor claims benefits under 35 USC §119(e) for provisional patentapplications, for any and all parent, grandparent, great-grandparent,etc. applications of the Related Application(s)). All subject matter ofthe Related Applications and of any and all parent, grandparent,great-grandparent, etc. applications of the Related Applications,including any priority claims, is incorporated herein by reference tothe extent such subject matter is not inconsistent herewith.

RELATED APPLICATIONS

-   -   For purposes of the USPTO extra-statutory requirements, the        present application constitutes a continuation-in-part of U.S.        patent application Ser. No. 13/445,174, entitled APPURTENANCES        FOR REPORTING INFORMATION REGARDING WOUND DRESSINGS, naming Paul        Duesterhoft, Nicholas Dykstra, Daniel Hawkins, Roderick A. Hyde,        Jordin T. Kare, Eric C. Leuthardt, Elizabeth L. Schubert,        Clarence T. Tegreene, and Lowell L. Wood, Jr. as inventors,        filed 12 April 2012, which is currently co-pending or is an        application of which a currently co-pending application is        entitled to the benefit of the filing date.    -   For purposes of the USPTO extra-statutory requirements, the        present application constitutes a continuation-in-part of U.S.        patent application Ser. No. 13/445,220, entitled COMPUTATIONAL        METHODS AND SYSTEMS FOR REPORTING INFORMATION REGARDING        APPURTENANCES TO WOUND DRESSINGS, naming Paul Duesterhoft,        Nicholas Dykstra, Daniel Hawkins, Roderick A. Hyde, Jordin T.        Kare, Eric C. Leuthardt, Elizabeth L. Schubert, Clarence T.        Tegreene, and Lowell L. Wood, Jr. as inventors, filed 12 Apr.        2012, which is currently co-pending or is an application of        which a currently co-pending application is entitled to the        benefit of the filing date.

The United States Patent Office (USPTO) has published a notice to theeffect that the USPTO's computer programs require that patent applicantsreference both a serial number and indicate whether an application is acontinuation, continuation-in-part, or divisional of a parentapplication. Stephen G. Kunin, Benefit of Prior-Filed Application, USPTOOfficial Gazette Mar. 18, 2003. The present Applicant Entity(hereinafter “Applicant”) has provided above a specific reference to theapplication(s) from which priority is being claimed as recited bystatute. Applicant understands that the statute is unambiguous in itsspecific reference language and does not require either a serial numberor any characterization, such as “continuation” or“continuation-in-part,” for claiming priority to U.S. patentapplications. Notwithstanding the foregoing, Applicant understands thatthe USPTO's computer programs have certain data entry requirements, andhence Applicant has provided designation(s) of a relationship betweenthe present application and its parent application(s) as set forthabove, but expressly points out that such designation(s) are not to beconstrued in any way as any type of commentary and/or admission as towhether or not the present application contains any new matter inaddition to the matter of its parent application(s).

SUMMARY

In one aspect, an appurtenance to a wound dressing includes, but is notlimited to: a substrate configured to attach to a wound dressing; afluid-activated voltaic cell attached to the substrate; a transmissionunit attached to a surface of the substrate, the transmission unitincluding circuitry and at least one antenna, the transmission unitconfigured to transmit a signal in response to current generated by thefluid-activated voltaic cell; and a projection operably attached to thefluid-activated voltaic cell, the projection of a size and shape toextend into an interior region of the wound dressing and configured tosample a fluid within the interior region of the wound dressing.

In one aspect, an appurtenance to a wound dressing includes, but is notlimited to: an enclosure of a height and width to fit substantiallywithin an interior region of a wound dressing, the enclosure includingat least one aperture configured to allow fluid to flow from theinterior region of the wound dressing into the enclosure; afluid-activated voltaic cell attached to one or more of the at least oneaperture; and a transmission unit attached to an internal surface of theenclosure, the transmission unit including circuitry and at least oneantenna, the transmission unit configured to transmit a signal inresponse to the fluid-activated voltaic cell.

In one aspect, an appurtenance to a wound dressing includes, but is notlimited to: an appurtenance configured to attach to a wound dressing,the appurtenance including a conduit configured to allow fluid flow froman interior region of a wound dressing into the appurtenance; afluid-activated voltaic cell including an internal chamber, the internalchamber attached to the conduit; and a radio frequency identification(RFID) unit attached to the fluid-activated voltaic cell and configuredto operate in response to current generated by the fluid-activatedvoltaic cell.

In one aspect, a method of monitoring a wound includes, but is notlimited to: conveying fluid from an interior region of a wound dressingto an appurtenance of the wound dressing; placing the fluid adjacent toa first electrode and a second electrode of a fluid-activated voltaiccell integral to the appurtenance; and utilizing current received fromthe fluid-activated voltaic cell directly to send a wireless signalbeyond the appurtenance.

In addition to the foregoing, other aspects of an appurtenance to awound dressing are described in the claims, drawings, and text forming apart of the present disclosure.

The foregoing summary is illustrative only and is not intended to be inany way limiting. In addition to the illustrative aspects, embodiments,and features described above, further aspects, embodiments, and featureswill become apparent by reference to the drawings and the followingdetailed description.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is a schematic of an appurtenance to a wound dressing in use witha wound.

FIG. 2A is a schematic of an appurtenance to a wound dressing prior toattachment to a wound dressing.

FIG. 2B is a schematic of an appurtenance to a wound dressing afterattachment to a wound dressing.

FIG. 3A is a schematic of an appurtenance to a wound dressing prior toattachment to a wound dressing.

FIG. 3B is a schematic of an appurtenance to a wound dressing afterattachment to a wound dressing.

FIG. 4 is a schematic of layers of a wound dressing and potentialplacement of appurtenances relative to the layers.

FIG. 5 is a schematic of an appurtenance to a wound dressing.

FIG. 6 is a schematic of an appurtenance to a wound dressing.

FIG. 7 is a schematic of an appurtenance to a wound dressing.

FIG. 8 is a schematic of an appurtenance to a wound dressing.

FIG. 9 is a schematic of an appurtenance to a wound dressing.

FIG. 10 is a schematic of an appurtenance to a wound dressing.

FIG. 11 is a schematic of an appurtenance to a wound dressing.

FIG. 12 is an illustration of an appurtenance to a wound dressing.

FIG. 13 is a schematic of an appurtenance to a wound dressing incommunication with a local unit.

FIG. 14 is a depiction of a local unit.

DETAILED DESCRIPTION

In the following detailed description, reference is made to theaccompanying drawings, which form a part hereof. In the drawings,similar symbols typically identify similar components, unless contextdictates otherwise. The illustrative embodiments described in thedetailed description, drawings, and claims are not meant to be limiting.Other embodiments may be utilized, and other changes may be made,without departing from the spirit or scope of the subject matterpresented here.

The use of the same symbols in different drawings typically indicatessimilar or identical items.

With reference now to FIG. 1, shown is an example of an appurtenance 120to a wound dressing 115, used on a wound 100, which can serve as acontext for introducing one or more processes and/or devices describedherein. As shown in FIG. 1, a body part 110, such as a leg, includes awound 100. A wound dressing 115, selected by a medical caregiver asappropriate in size, shape and type for the wound 100, has anappurtenance 120 attached to generate an appurtenance affixed to a wounddressing combination unit, 125. The appurtenance 120 can be attached tothe wound dressing 115 with a mechanical attachment. For example, amechanical attachment can include mechanical attachment features shapedlike prongs, barbs, bristles, spikes, or spurs. An appurtenance 120 caninclude one or more mechanical attachment features on a surface of theappurtenance configured to mate with a surface of the wound dressing115. The appurtenance 120 can be attached to the wound dressing 115 witha chemical attachment, which can include chemical attachment featuressuch as a pressure-sensitive adhesive, a contact adhesive, or aquick-drying adhesive. An appurtenance 120 can include one or morechemical attachment features on a surface of the appurtenance configuredto mate with a surface of the wound dressing 115. The appurtenance 120is a separate and distinct element that can be attached to the wounddressing 115 in a manner sufficient for operation during the use of aspecific wound dressing 115. The appurtenance 120 is a separate anddistinct element that can be attached to the wound dressing 115 in anirreversible manner. For example, the appurtenance-wound dressingcombination unit, 125, can be disposed of after use. Immediate disposalafter use can be desirable to minimize biosafety, contamination andbiohazard issues. The appurtenance 120 is a separate and distinctelement that can be attached to the wound dressing 115 in a reversiblemanner. For example, the appurtenance-wound dressing combination unit,125, can be taken apart into its component wound dressing 115 andappurtenance 120 after use. For example, the appurtenance 120 can beconfigured for reuse with a new wound dressing 115. The appurtenance 120can be configured for reuse after treatment, such as after disinfection,cleaning, or sterilization. An appurtenance 120 to a wound dressing 115can be reused, for example, on a succession of wound dressings 115 usedby the same patient.

The appurtenance 120 is configured for functional use only incombination with a wound dressing, such as when attached to the wounddressing 115. The appurtenance 120 is of a size, shape and material forfunctional use only in combination with a wound dressing, such as whenattached to the wound dressing 115. The appurtenance 120 is configuredto operate in conjunction with the wound dressing 115. The appurtenance120 is appended to the wound dressing 115 to generate anappurtenance-wound dressing combination unit 125, as illustrated in thelower right region of FIG. 1. The appurtenance 120 can include at leastone region that projects into the structure of the wound dressing 115.In some embodiments, the region that projects into the structure of thewound dressing 115 is of a size and shape to be entirely enclosed withinthe structure of the wound dressing 115. In some embodiments, the regionthat projects into the structure of the wound dressing 115 is of a sizeand shape to project through the wound dressing 115, for example to aregion adjacent to a wound. In some embodiments, the region thatprojects into the structure of the wound dressing 115 is of a size andshape to project through the wound dressing 115, for example to a woundbed region. In some embodiments, the region that projects into thestructure of the wound dressing 115 is of a size and shape to projectthrough a portion of the wound dressing 115, for example to a sinus orcavity of the wound bed. In some embodiments, the region that projectsinto the structure of the wound dressing 115 is of a size and shape toproject through a portion of the wound dressing 115, for example to adressing placed within a sinus or cavity of the wound bed. In someembodiments, the region that projects into the structure of the wounddressing 115 is of a size and shape to project through a portion of thewound dressing 115, for example to a layer placed adjacent to the woundsurface. The appurtenance 120 affixed to the wound dressing 115 forms anintegrated unit of the appurtenance and the wound dressing as acombination unit 125 (see, e.g. FIGS. 2A, 2B, 3A, 3B, 4, 5, 6 and 8). Insome embodiments, the wound dressing-appurtenance combination unit 125is not readily separable, and the individual wound dressing 115 andappurtenance 120 are not suitable for separation and individual useafter they have been joined together. As illustrated in the lowerportion of FIG. 1, once the appurtenance 120 is affixed to the wounddressing 115, the appurtenance and the wound dressing together as acombination unit 125 are used to cover and monitor the wound 100.

In some aspects, an appurtenance 120 to a wound dressing 115 isconfigured to monitor one or more aspects of a wound 100. Anappurtenance 120 to a wound dressing 115 can be used by a caregiver or apatient to monitor a wound 100. In some aspects, an appurtenance 120 toa wound dressing 115 is configured to monitor one or more aspects of awound dressing 115. An appurtenance 120 to a wound dressing 115 can beused by a caregiver, including a patient, to monitor a wound dressing115. An appurtenance 120 to a wound dressing 115 is configured to allowa user, such as a caregiver or patient, to monitor a wound dressing andthe adjacent wound without disturbing the wound dressing 115 such asthrough removing the dressing 115 from the patient's wound 100. Thisapproach, inter alia, improves comfort to the patient, reduces thechance of accidental infection in or contamination from uncoveredwounds, and minimizes time requirements in wound care. In some aspects,an appurtenance 120 to a wound dressing 115 includes a transmitter thatsends a signal to a device used by a caregiver or patient to monitor thewound dressing from the same room as the patient. In some aspects, anappurtenance 120 to a wound dressing 115 includes a transmitter thatsends a signal to a device used by a caregiver remotely, such as througha pager, remote computing device, cell phone, or dedicated remotesignaling device. The signal transmitter sends a signal containinginformation associated a wound and/or adjacent wound dressing such thata caregiver is able to receive, directly or indirectly, informationrelating to monitoring a wound and adjacent wound dressing at a distancefrom the patient, without disturbing the patient and with minimal timespent analyzing the wound 100 or wound dressing 115.

In some aspects, an appurtenance 120 to a wound dressing 115 is part ofa system configured to automatically process and save informationrelating to an appurtenance 120 and the related wound dressing 115 to amedical record system, such as a medical records database. Thisautomatic process reduces the potential for accidental loss or error indata entry regarding wound care, and reduces the time required by acaregiver in data entry into a record.

The wound dressing with the affixed appurtenance combination unit 125 isused to cover the wound 100 on the body part 110. The wound dressingwith the affixed appurtenance combination unit 125 can be secured to thebody part 110 in a routine manner for the type of wound dressing 115generally, such as through adhesive integral to the wound dressing 115or with additional adhesive, wrappings, tapes or glues as generallyapplicable to the type of wound dressing 115 utilized in a given medicalsituation. Although not illustrated in FIG. 1, the wound dressing withthe affixed appurtenance combination unit 125 can similarly be removedusing standard removal procedures, such as with gentle pressure, gentlepulling, unwrapping, allowing it to loosen over time, or bio-compatiblesolvents. The appurtenances 120 described herein can be single-use anddisposable along with the affixed wound dressing 115. In someembodiments, the appurtenances 120 described herein can be removed froma first wound dressing and then reconditioned, such as through cleaningor sterilization, and reused with a second wound dressing. In someembodiments, an appurtenance 120 can be reused for multiple wounddressings used on a single wound from a patient. In some embodiments, anappurtenance 120 can be reused after replacement of one or more parts ofthe appurtenance. The appurtenances 120 described herein are generallyintended to be operable for the period of time a given wound dressing115 is in use under standard conditions and time periods. After a wounddressing with the irreversibly affixed appurtenance combination unit,125 is removed from the body part 110, it can be disposed of as a unitwith routine disposal methods.

It is envisioned that the appurtenances 120 described herein will beutilized while affixed to wound dressings 115 over wounds 100 of avariety of types, and operable to assist in the monitoring of wounds ofa variety of types. For example, appurtenances 120 can be used inconjunction with wound dressings 115 to assist in monitoring acutewounds, such as those resulting from accidental injury or surgery. Forexample, appurtenances 120 can be used in conjunction with wounddressings 115 to assist in monitoring wounds closed by primaryintention. For example, the appurtenances 120 can be used to assist inmonitoring wound dressings over surgical wounds, such as incisions andsurgical stitches. For example, the appurtenances 120 can be used toassist in monitoring wound dressings over acute wounds from injury, suchas burn injuries, lacerations, or penetrating wounds. For example,appurtenances 120 can be used in conjunction with wound dressings 115 toassist in monitoring wounds closed by secondary intention. Theappurtenances 120 can also be used to assist in monitoring wounddressings over chronic wounds, such as those arising from chronicmedical conditions and situations. For example, the appurtenances can beused to monitor the status of wound dressings covering venous legulcers, diabetic foot ulcers, pressure ulcers or arterial ulcers. See:“Advances in Wound Healing Techniques,” publication D11A, Frost andSullivan, 2008; “An Overview of Ulceration Wounds,” Publication M4BB-54,Frost and Sullivan 2009; and “US Advanced Wound Care Market,”Publication N71A-54, Frost and Sullivan 2010, which are eachincorporated herein by reference.

The appurtenances 120 described herein can be useful in conjunction withan affixed wound dressing as a combination unit 125 to monitor potentialproblems with a wound, such as excessive bleeding or other fluidformation that would be present in the wound dressing, or the presenceof conditions in the dressing that indicate infection in an adjacentwound. See: Collier, “Recognition and Management of Wound Infections,”World Wide Wounds, pages 1-9, (January 2004); and Gray, “Assessment,Diagnosis and Treatment of Infection,” Wounds UK, vol. 7, no. 2,supplement, (2011), which are each incorporated herein by reference. Forexample, some types of wound discharge can indicate infection. See, forexample, Cutting and Harding, “Criteria for Identifying WoundInfection,” Journal of Wound Care, vol. 3, no. 4, 198-201 (1994), whichis incorporated herein by reference. The appurtenances 120 as part ofcombination units 125 and related systems described herein can be usedin conjunction with readily available types of wound dressings tomonitor aspects of the affixed wound dressing, including parameters thatindicate that a person should physically examine the wound dressing,such as excessive wetness. The appurtenances 120 as well as relatedsystems described herein can be used in conjunction with readilyavailable types of wound dressings to monitor aspects of the affixedwound dressing, including indications that the wound dressing should bechanged (i.e. excessively wet, dry, or soiled). In some embodiments, theappurtenances 120 include additional sensors positioned to detect anaspect of the fluid from the affixed wound dressing, such as thepresence of analytes, temperature, or fluid pressure within a conduit orprojection.

The appurtenances described herein include transmission units configuredto transmit signals, and thereby report information regarding the statusof the affixed wound dressing or wound, to associated systems. Theresulting information reporting can be used, in some embodiments, tosupplement the medical record for a patient in an automated system andautomatic process. The resulting information reporting can be used, insome embodiments, to automatically notify a caregiver that the status ofthe wound dressing has altered, indicating that a person shouldphysically inspect the wound dressing.

As used herein, a caregiver includes at least one of a patient, acaregiver, and medical personnel. A caregiver can utilize someembodiments of the appurtenances and related systems described herein inrelation with multiple types of wound dressings. Appurtenances can befabricated in shapes and sizes to conform to a variety of standard wounddressing sizes, shapes and types. Appurtenances can be fabricated with,for example, transmission units, antennas and sensors appropriate foruse with a variety of wound dressings. Appurtenances can be fabricatedwith, for example, transmission units, antennas and sensors appropriatefor different medical situations and monitoring requirements.Appurtenances can be fabricated with, for example, one or moreprojections of a size, shape and material appropriate for use with avariety of wound dressings. While it is envisioned that everyappurtenance will not be appropriate for use with every wound dressing(for example due to size, shape or material compatibility), a givenappurtenance is expected to be suitable for use with a range ofpotential wound dressings. For example, a given appurtenance of aspecific size, shape and fabrication, including type of transmissionunit, sensors, and projection(s), should be suitable for use with avariety of wound dressings of conforming sizes, shapes and types.Generally, any specific appurtenance embodiment is not expected to onlyconform to use with a unique wound dressing of a specific size, shapeand type. Instead, it is expected that a specific appurtenanceembodiment will be suitable for use with a range of wound dressings.Similarly, it is expected that a specific appurtenance embodiment willbe suitable for use with a range of wound and wound dressing monitoringrequirements.

In the attached drawings, an appurtenance 120 is generally illustratedas affixed to an outer surface of a wound dressing 115, for example anouter surface distal to a surface of the body part 110 adjacent to thewound 100. However, in some embodiments, an appurtenance 120 can beconfigured to attach to one or more surfaces of a wound dressing 115adjacent to a surface of the body part 110 adjacent to the wound 100.For example, in embodiments wherein an appurtenance 120 is configured tobe attached to a wound dressing 115 of a substantially rectangular,ovoid, or raised conformation, an appurtenance 120 can be configured tobe attached to a side surface of the wound dressing 115. For example, inembodiments wherein an appurtenance 120 is configured to be attached toa wound dressing 115 with an unusually strong or thick outer coverlayer, the appurtenance 120 can be configured to attach to an undersideor interior region of the wound dressing 115. In some embodiments, anappurtenance is configured to attach to a surface of a wound dressing115 in contact with the surface of the body part 110. In someembodiments, an appurtenance is configured to attach to an internalsurface of a wound dressing 115, for example between layers. See FIG. 4.

For example, the appurtenances described herein can be configured to beaffixed to a dry gauze dressing, which may or may not include an outercover layer. For example, the appurtenances described herein can beconfigured to be attached to a dry silicone or other solid foamdressing, which may or may not include an outer cover layer. Forexample, the appurtenances described herein can be configured to beaffixed to a wound dressing used to close a small or thin wound orsurgical incision, such as a butterfly dressing (e.g. SteriStrip™adhesive strips, available from Nexcare™, part of 3M Corporation). Forexample, appurtenances such as those described herein can be configuredto be affixed to a dressing configured to maintain moisture or othermaterials adjacent to the wound surface. For example, appurtenances suchas those described herein can be configured to be used with hydrogelwound dressings, for example Aquaflo™ Hydrogel Wound Dressing by KendallCorporation, or Elasto-Gel™ Hydrogel Occlusive Dressing by SouthwestTechnologies. For example, appurtenances such as those described hereincan be affixed to wound dressings including hydrocolloids, for exampleDuoDERM CGF Sterile Hydrocolloid Dressing manufactured by DuoDERMCorporation. For example, appurtenances such as those described hereincan be configured to be used with wound dressings containing one or moremedicinal agents, such as antibiotics. For example, appurtenances suchas those described herein can be used with wound dressings impregnatedwith PHMB (Polyhexamethylene Biguanide), such as Telfa™ A.M.D.antimicrobial wound dressings, manufactured by Kendall Corporation. Forexample, appurtenances such as those described herein can be configuredto be used with wound dressings including ionic silver, such as Maxorb™Extra Ag wound dressings manufactured by Medline Corporation.Appurtenances such as those described herein can be configured to beaffixed to wound dressings over wounds wherein the tissue of the woundis being directly monitored using other devices, for example asdescribed in U.S. Pat. No. 6,963,772 to Bloom et al., titled“User-retainable Temperature and Impedance Monitoring Methods andDevices,” which is incorporated herein by reference. Appurtenances suchas those described herein can be configured to be affixed to wounddressings over wounds wherein the patient is being directly monitoredusing other devices, for example as described in U.S. Pat. No. 7,030,764to Smith and Cooper, titled “Apparatus and Method for Reducing the Riskof Decubitus Ulcers;” U.S. Pat. No. 7,297,112 to Zhou et al., titled“Embedded Bio-Sensor System;” U.S. Pat. Nos. 7,372,780, 8,014,234 and7,813,226 to Braunberger, titled “Timing System and Device and Methodfor Making the Same;” U.S. Pat. No. 7,666,151 to Sullivan et al., titled“Devices and Methods for Passive Patient Monitoring;” U.S. Pat. No.7,703,334 to Cochran, titled “Bandage Type Sensor Arrangement andCarrier Assembly Therefore, and Method of Manufacture;” andInternational Patent Publication No. WO 2005/009328 to Nikolic, titled“ABT-Anti-Bedsore Timer,” which are each incorporated herein byreference. Appurtenances such as those described herein can also be usedin conjunction with a system to monitor assets within a health carefacility, for example as described in US Patent Application No.2007/0247316 to Wildman et al., titled “Article Locating and TrackingApparatus and Method,” which is incorporated herein by reference.

Wound dressings 115 such as those described herein are generally usedfor a relatively short period of time, on the order of hours or days,and then removed for disposal. Similarly, a wound dressing with anaffixed appurtenance combination unit 125 should be configured for useover the course of hours or days and then removed and disposed of usingstandard methods. A wound dressing with an affixed appurtenance can beconfigured for single use and to be disposable after use. For example, acaregiver can require a new wound dressing every 24 hours (1 day) for anacute wound. Any wound dressing utilized in this type of situationwould, consequently, be of a size, weight and shape to remain affixed tothe wound region over the course of at least a 24 hour period and thenremoved for disposal. An appurtenance to a wound dressing intended foruse over the course of a 24 hour time period, similarly should be of asize, shape, material fabrication, and capabilities to function whileaffixed to the wound dressing over the 24 hour period that the dressingis in use. An appurtenance to a wound dressing can be configured to belightweight and of a low form factor to minimize disruption to the wounddressing. For example, an appurtenance can be configured to weigh lessthan approximately 30 grams, or less than approximately 40 grams, orless than approximately 50 grams. As an additional example, a caregivercan decide that for another type of wound, such as a chronic wound, thewound dressing needs to be removed and replaced once every 2 days, every3 days, or every 4 days, or every 5 days, or every 6 days, or every 7days. Correspondingly, an appurtenance affixed to a wound dressingintended for use over the course of at least 2 to 7 days should be of asize, shape, material fabrication, and capabilities to function whileaffixed to the wound dressing over at least the 2 to 7 day period thatthe dressing is in use. In embodiments wherein an appurtenance isintended for reuse, such as reuse on a second or subsequent wounddressing used over a wound, the appurtenance should be of a size, shape,material fabrication and capabilities to function during the entireintended use, including the time period of removal from a first wounddressing and application to a second wound dressing.

FIGS. 2A and 2B depict further aspects of some embodiments ofappurtenances to wound dressings. FIGS. 2A and 2B depict cross-sectionviews of an appurtenance 120 to a wound dressing 115. As illustrated inFIG. 2A, the appurtenance 120 includes a substantially planar sectionand a projection 200. The substantially planar section includes asurface 230 configured to substantially conform with an outer surface ofthe wound dressing 115. In some embodiments, the surface 230 of theappurtenance 120 configured to conform with an outer surface of thewound dressing 115 can include adhesive of a type expected toirreversibly adhere to the surface of the wound dressing 115. In someembodiments, the surface 230 of the appurtenance 120 configured toconform with an outer surface of the wound dressing 115 can includeadhesive of a type expected to adhere to the surface of the wounddressing 115 for a period of time, and to be removable. In someembodiments, the surface 230 of the appurtenance 120 configured toconform with an outer surface of the wound dressing 115 can includebarbs, hooks, pins, prongs or other extensions configured to adhere orfix onto the outer surface of the wound dressing 115. For example, anappurtenance 120 configured to conform with an outer surface of thewound dressing 115 can include barbs, hooks, pins, prongs or otherextensions that irreversibly adhere to the outer surface of the wounddressing 115, such as by imbedding into the outer surface. For example,an appurtenance 120 configured to conform with an outer surface of thewound dressing 115 can include barbs, hooks, pins, prongs or otherextensions that reversibly adhere to the outer surface of the wounddressing 115, such as by reversibly interacting with extensionsprojecting from the outer surface.

The appurtenance 120 depicted in FIGS. 2A and 2B includes a projection200. As shown in FIGS. 2A and 2B, the projection extends from a surface230 of the appurtenance 120 configured to conform with an outer surfaceof the wound dressing 115. The single projection depicted in FIGS. 2Aand 2B projects at an angle from the plane formed by the substantiallyplanar section of the appurtenance 120 conforming to the surface of thewound dressing 115. This angle is depicted in FIG. 2A as θ. In FIGS. 2Aand 2B, for example, the angle shown as θ is approximately 135 degrees.However, as will be more evident from further description below (see,e.g. in relation to FIG. 12), in some embodiments an appurtenance 120can include a plurality of projections 200. Depending on the embodiment,the projections 200 can also be at a variety of angles relative to thesection of the appurtenance 120 conforming to the surface of the wounddressing 115. For example, in some embodiments, one or more projectionscan be at angles less than approximately 135 degrees, betweenapproximately 135 degrees and approximately 90 degrees, or substantiallyat approximately 90 degree angles relative to a planar section of theappurtenance 120. In some embodiments, an appurtenance 120 includes asubstantially planar region including a transmission unit, wherein thesubstantially planar region is configured to conform with an outersurface of the wound dressing 115, and one or more projections 200projecting substantially perpendicular to the surface 230 configured toconform with an outer surface of the wound dressing 115. Depending onthe embodiment, the projections 200 can project in a directionsubstantially away from the surface of the appurtenance configured toconform with an outer surface of the wound dressing 115 (e.g. as inFIGS. 2A and 2B), or angle in a direction substantially perpendicular tothe surface 230 configured to conform with an outer surface of the wounddressing 115 of the appurtenance. Some embodiments include at least oneprojection 200 which is curvilinear. Some embodiments include at leastone projection 200 which is a composite shape. In embodiments includingone or more projections that are not substantially straight, an angle(e.g. θ as illustrated in FIG. 2A) of the projection 200 can bedetermined by the angle formed at the base of the projection immediatelyadjacent to the surface of the appurtenance configured to conform withan outer surface of the wound dressing 115.

The projection 200 can be a substantially hollow tubular structure.Although not illustrated in FIGS. 2A and 2B in this view, asubstantially hollow tubular structure of the projection 200 includes anopening on the distal end of the projection 200. While the projection200 depicted in FIGS. 2A and 2B can be a substantially tubularstructure, in some embodiments projections can be of different shapesand conformations. For example, a projection 200 can be solid, tubular,conical, cylindrical, tapered, curved, angular or other shape orcombination of shapes as appropriate to the specific embodiment.Embodiments including a plurality of projections can include projectionsof different sizes and shapes. A projection 120 can be substantiallystraight and form a substantially linear internal channel (e.g. asdepicted in FIGS. 2A, 2B, 8 and 9), or it can be curved and form asubstantially curvilinear internal channel. The drawings illustratedherein are not to scale. The drawings illustrated herein representrelationships and shapes of the items described. Although not expresslyillustrated herein, a projection 200 can be relatively large relative tothe total size of the appurtenance. For example, the volume of aprojection or a group of projections attached to an appurtenance can be51%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90%, 95% or 100% of the volumeof the portion of the appurtenance configured to conform with an outersurface of a wound dressing (e.g. the substantially planar region asillustrated in FIGS. 2A and 2B). Similarly, a projection 200 can berelatively small relative to the total size of the appurtenance. Forexample, the volume of a projection or a group of projections attachedto an appurtenance can be 49%, 45%, 40%, 35%, 30%, 25%, 20%, 15%, 10%,or 5% of the volume of the portion of the appurtenance configured toconform with an outer surface of a wound dressing (e.g. thesubstantially planar region as illustrated in FIGS. 2A and 2B). In someembodiments, a projection 200 is located at an edge region of thesubstantially planar region of the appurtenance 120, and in someembodiments a projection 200 is located substantially centrally to theplanar surface 230 of the appurtenance 120 configured to conform with anouter surface of the wound dressing 115. In some embodiments, asubstantially planar appurtenance 120 includes at least one projection200 wherein the entire appurtenance 120 is of a size and shape to besecured against an external surface of a wound dressing 115 with force,for example from a human thumb or finger.

In some embodiments, an appurtenance 120 can be fabricated with one ormore regions configured for the attachment of different modules. In someembodiments, an appurtenance 120 includes modules that are configuredfor removal and replacement. In some embodiments, an appurtenance 120includes modules that are configured to improve efficiency infabrication of the appurtenance 120. During fabrication, a basicappurtenance structure can be utilized and different specific modulesadded as desired in a particular embodiment. For example, anappurtenance 120 can be fabricated with at least one region configuredto attach a projection. For example, a region configured to attach aprojection can include a region with a surface conforming to an outersurface of the projection. For example, a region configured to attach aprojection can include a conduit configured to align with the hollowinterior of the projection. The region of the appurtenance 120configured to attach a projection can be configured for attachment ofdifferent projection types, depending on the embodiment. For example,the region of the appurtenance 120 configured to attach a projection canbe configured for attachment of projections of different lengths ordifferent materials as desired in the construction of a particularembodiment. In some embodiments, an appurtenance 120 can have multipleregions configured for attachment of multiple projections of differenttypes. In some embodiments, an appurtenance 120 can have one or moreremovable antenna modules. For example, an appurtenance 120 can have oneor more removable transmission units, such as radio frequencyidentification (RFID) units. In some embodiments, a module can include aspacer element, or a component configured to assist in physicallypositioning one or more other modules.

An appurtenance 120 can be fabricated from a variety of materials, asappropriate to an embodiment. An appurtenance 120 can be fabricated, forexample, substantially from a plastic material. For example, astructural portion, such as a shell or base can be fabricated from aplastic material. For example, one or more projections can be fabricatedfrom a plastic material. An appurtenance 120 can be fabricated, forexample, from one or more acrylics, polyesters, silicones, polyurethanesand halogenated plastics. An appurtenance 120 can include one or moreprojections 200 fabricated, for example, from one or more plasticmaterials. An appurtenance 120 can include one or more projections 200fabricated, for example, from one or more acrylics, polyesters,silicones, polyurethanes and halogenated plastics. An appurtenance 120can be fabricated from one or more bio-compatible materials, for examplebio-compatible plastics, resins, epoxies and metals. An appurtenance 120can be fabricated from one or more composite materials, such as plasticwith an overlay of epoxy or plastic with an overlay of one or moremetals. An appurtenance 120 including a transmission unit can include,for example, one or more metal components, for example as circuitry oras one or more antennas. An appurtenance 120 including a transmissionunit can include, for example, stainless steel, copper or zinc alloy. Anappurtenance 120 can be fabricated from one or more ceramic materials,such as within a transmission unit. Generally, it is envisioned thatmaterials with low weight will be suitable for a variety of appurtenanceembodiments, so as to reduce weight and associated physical stress on awound dressing. Similarly, it is envisioned that materials withsufficient strength and toughness to be fabricated into small and thincomponents will be desirable for fabrication of appurtenanceembodiments. As the appurtenances are to be permanently affixed to thewound dressings and disposed of with the wound dressings, materials thatdo not require special handling or disposal are preferable in mostembodiments.

In some embodiments, the appurtenance 120 includes a substrate, (e.g.250) that is configured to attach to the wound dressing 115. Forexample, the substrate can be configured as a support for other featuresof the appurtenance 120. For example, the substrate can stabilize otherfeatures of the appurtenance 120 in their relative positions. Forexample, the substrate can cover and protect other features of theappurtenance 120. In some embodiments, the substrate includes asubstantially planar structure wherein the area of surface 230 is lessthan the area of the wound dressing 115 (see, e.g. FIG. 5). In someembodiments, the substrate is configured to irreversibly attach directlyto an external surface of the wound dressing 115. In some embodiments,the substrate is configured to chemically attach to the wound dressing115. In some embodiments, the substrate includes an adhesive on asurface conforming to an external surface of the wound dressing 115(e.g. surface 230 in FIG. 2A). For example, the surface conforming to anexternal surface of the wound dressing 115 can include a glue, epoxy,sealant, mucilage, paste or other binder material. In some embodiments,the surface of the substrate conforming to an external surface of thewound dressing 115 can include an adhesive covered by a removableprotective sheet configured for detachment and exposure of the adhesivewhen the appurtenance 120 is attached to the wound dressing 115. In someembodiments, the substrate is configured to mechanically attach to thewound dressing 115. In some embodiments, the surface 230 of thesubstrate of the appurtenance 120 configured to conform with an outersurface of the wound dressing 115 can include barbs, hooks, pins, prongsor other extensions configured to adhere or fix into the outer surfaceof the wound dressing 115. In some embodiments, the substrate isconfigured to integrate within the wound dressing 115 (see, e.g. FIG.4). In some embodiments, the substrate is configured to attach to anouter surface of the wound dressing 115. In some embodiments, thesurface 230 of the substrate of the appurtenance 120 configured toconform with a surface of the wound dressing 115 can include a mixtureor combination of any of the above.

In some embodiments, the substrate includes a flexible material. Forexample, the substrate can include a pliable plastic, a woven fabricmaterial, soft mesh or other flexible material. In some embodiments, thesubstrate includes a rigid material. For example, the substrate caninclude at least one rigid plastic material in a location configured toprovide support for a portion of the appurtenance. For example, thesubstrate can include at least one rigid plastic material at a locationconfigured to attach a projection, the rigid plastic configured toprovide physical support for the attached projection. In someembodiments, the substrate includes at least one bio-compatiblematerial. For example, the substrate can include one or morebio-compatible plastic materials, one or more bio-compatible fabricmaterials, or one or more bio-compatible metals.

FIG. 2A depicts a cross section view of an appurtenance 120 adjacent toa wound dressing 115. As shown in FIG. 2A, the wound dressing 115includes a dressing layer 220 and an outer layer 210. Not all wounddressings 115 should be expected to include multiple layers, and it isto be expected that some wound dressings 115 substantially include onlya wound dressing material and not additional layers, structures orcoverings. However, as illustrated in FIGS. 2A and 2B, in someembodiments wound dressings 115 include a plurality of layers. Forexample, a wound dressing 115 can include one or more outer layers 210configured to protect and isolate the wound dressing layer(s) frommicrobes, external dirt and debris, dryness, wetness or other externalfactors. An outer layer can be fabricated from materials such as firmplastics or mesh materials. An outer layer can include a surface largerthan the surface of the wound dressing layer, and can include adhesiveson that surface configured to adhere the entire wound dressing to a bodysurface. A wound dressing 115 can include one or more layers of wounddressing 220 materials, such as gauze, films, foams, or sponges. A wounddressing 115 can include one or more layers of hydrogels, colloid gels,and medicinal agents impregnated within one or more layers of the wounddressing 220 or on a surface of the wound dressing 220 configured toface a wound.

A surface 230 of an appurtenance 120 can be configured to conform to thesurface of the outer layer 210 of a wound dressing 115. For example, thesurface can be of a size and shape that substantially conforms with thesurface of the wound dressing 115. A surface 230 of an appurtenance 120can include barbs, hooks, pins, prongs or other extensions configured toreversibly or irreversibly stick into the outer surface of the wounddressing 115. A surface 230 of an appurtenance 120 can include one ormore adhesives of a type to attach the appurtenance 120 to the wounddressing 115.

FIG. 2B illustrates the appurtenance 120 and the wound dressing 115 ofFIG. 2A after the appurtenance 120 is affixed to the wound dressing 125.As illustrated in FIG. 2B, a projection 200 of an appurtenance 120 canbe configured to pierce through the outer layer 210 and into a wounddressing layer 220. A projection 200 of an appurtenance 120 can be of asize and shape to project from the outer surface of the wound dressing115 to within layers of the wound dressing 115. A projection 200 can beof a size and shape to extend into an interior region of the wounddressing 115. A projection 200 can be of a size and shape to projectwithin an interior region of the wound dressing 115. As shown in FIG.2B, a projection 200 can be of a size and shape to project underneathone or more superficial structures of the wound dressing 115 (such as anouter layer 210) when the wound dressing 115 is in use. A projection 100can be of a size and shape to project through a width of the wounddressing 115 when the appurtenance 120 is attached to the wound dressing125. Also as illustrated in FIG. 2B, a projection 200 extending withinthe layers of the wound dressing 125 can be positioned so that fluids,(depicted as dotted arrows), can enter a hollow within the projection200 through capillary action.

FIG. 2B also illustrates that in some embodiments a cover 240 isattached to the surface of the appurtenance 120 as well as to thesurface of the wound dressing, such as to an outer layer of the wounddressing 210. An appurtenance 120 can include a substantially planarcover, the cover including an adhesive on a surface conforming to asurface of a wound dressing, the substantially planar cover configuredto cover a location where the projection extends into the wounddressing. A cover 240 can be fabricated, for example, from a flexibleplastic or mesh material. A cover 240 can be fabricated, for example,from an inflexible plastic or mesh material and configured in a size andshape to conform with the surfaces of the appurtenance 120 as well as tothe surface of the wound dressing 115. A cover 240 can include adhesiveon a surface facing the appurtenance and the wound dressing, theadhesive configured to attach the cover to the appurtenance and to thewound dressing. A cover 240 can be configured to stabilize the positionof the appurtenance 120 relative to the wound dressing 115 when theappurtenance is affixed to the wound dressing 125 (e.g. as in FIG. 2B).A cover 240 can be configured to secure the appurtenance 120 relative tothe wound dressing 115 when the appurtenance is affixed to the wounddressing 125 (e.g. as in FIG. 2B). A cover 240 can be configured to sealthe juncture between the appurtenance 120 and the wound dressing 115,for example from dirt, debris, wetness or microbes that can enter theinterior of the wound dressing if the juncture is not sealed. A cover240 can be configured to seal any potential gaps between the projection200 of the appurtenance 120 and the wound dressing 115, for example toseal any potential gaps from dirt, debris, external wetness or microbesthat can enter the interior of the wound dressing if the gap is notsealed.

In some embodiments, an appurtenance 120 to a wound dressing 115 issubstantially sterilized prior to use. For example, the appurtenance 120can be treated with one or more chemical disinfectants or UV surfaceradiation for a period of time sufficient to substantially sterilize theappurtenance 120 prior to use. For example, the appurtenance 120 can betreated with one or more antimicrobial gasses, for example ethyleneoxide (ETO), prior to use. For example, the appurtenance 120 can betreated with a chemical sterilizing agent, such as hydrogen peroxide inliquid or vapor form, prior to use. For example, the appurtenance 120can be treated with steam as an anti-infective prior to use. Forexample, the appurtenance 120 can be irradiated prior to use, such aswith gamma rays, electron beams, ultraviolet rays, or X-rays. In someembodiments, an appurtenance 120 to a wound dressing 115 includes asterile wrapper. For example, an appurtenance 120 to a wound dressing115 can be stored and/or transported within a sterile wrapper, such as afirm paper wrapper or a plastic film. A sterile wrapper configured forstorage and/or transport of an appurtenance can be treated to minimizecontamination, for example coated with one or more anti-microbialagents.

FIGS. 3A and 3B illustrate aspects of some embodiments of anappurtenance 120 to a wound dressing 115 in a cross-sectional view. Insome embodiments, an appurtenance 120 includes an enclosure of a heightand width to fit substantially within an interior region of a wounddressing 115. FIG. 3A depicts an appurtenance 120 of a size and shape tosubstantially penetrate an outer cover 210 and into a dressing region220 of a wound dressing 115. The appurtenance 120 depicted in FIGS. 3Aand 3B is a cross section view of a substantially conical shape with anopening at the lower region of the cone (downward in FIGS. 3A and 3B).The main structure of the appurtenance is depicted as 250. Asillustrated in FIG. 3A and FIG. 3B, some embodiments include a cover240. A cover 240 can be of a size and shape to seal the surface of theappurtenance 120 exposed at the surface of the wound dressing. FIG. 3Bdepicts the appurtenance 120 affixed to the wound dressing 125. Theappurtenance 120 depicted in FIG. 3B projects through the outer layer210 of the wound dressing and into the interior wound dressing layer220. Also as illustrated in FIG. 3B, an appurtenance 120 extendingwithin the layers of the wound dressing 125 can be positioned so thatfluids, depicted as dotted arrows, can enter an opening or aperture inthe appurtenance 120 through capillary action. See also FIG. 7.

FIG. 4 depicts aspects of a wound dressing 115 and some potentialpositions of an appurtenance 120A, 120B relative to the wound dressing115. As shown in FIG. 4, a wound dressing 115 can include an outer layer210, a dressing layer 220 and a wound contact layer 400. For example,the outer layer 210 can include a plastic film or mesh configured toprotect the external surface of the wound dressing 115. The outer layer210 can include at least one exterior surface 410 positioned away fromthe wound 100 when the wound dressing 115 is in use. For example, thedressing layer 220 can include one or more layers of gauze or absorbentmaterial. For example, the dressing layer 220 can include a hydrogel.For example, the dressing layer 220 can include one or more layers offoam dressing. For example, the wound contact layer 400 can include aplastic mesh film configured to reduce chafing or adherence of the wounddressing 115 to the wound 100. For example, the wound contact layer 400can include a surface 420 configured to substantially conform with anouter surface of the wound 100. For example, the wound contact layer 400can include a surface 420 configured as a non-planar surface tosubstantially conform with an outer surface of the wound 100. Forexample, the wound contact layer 400 can include a surface 420 includinga flexible material expected to substantially conform with an outersurface of the wound 100, such as a soft foam or gel material. As shownin FIG. 4, some embodiments of the appurtenances 120A, 120B describedherein are configured to be positioned within the layers of a wounddressing 115. As shown in FIG. 4, an appurtenance 120 A can bepositioned between an outer layer 210 and a dressing layer 220 of awound dressing 115. Also as shown in FIG. 4, an appurtenance 120 A canbe positioned between a dressing layer 220 and a wound contact layer 400of a wound dressing 115. During use, the wound dressing 115 is condensedso that all of the layers 210, 220, 400 are positioned adjacent to eachother and also to any appurtenance 120 A, 120 B placed between thelayers 210, 220, 400. The wound dressing 115 with attached appurtenance120 A, 120 B is then reversibly affixed to the surface of a body part110 and covering a wound 100.

FIG. 5 illustrates aspects of an appurtenance 120 affixed to a wounddressing unit 125. The view illustrated in FIG. 5 is a substantiallytop-down view, as seen from the top of an appurtenance affixed to awound dressing unit 125 looking down on to the unit. The side of thewound dressing-appurtenance combination unit 125 illustrated in FIG. 5is the side that would be away from a wound during use (e.g. surface 410as shown in FIG. 4). The side of the wound dressing-appurtenancecombination unit 125 illustrated in FIG. 5 is the distal face to thesurface of the unit configured for use adjacent to a body part. As shownin FIG. 5, a wound dressing can include a wound covering region 500 andan edge region 510. The wound covering region 500 can include one ormore layers of a wound dressing, such as gauze, foam, hydrocolloids, andother types of wound dressings singly or in combination. The edge region510 can include, for example, a structural region configured to provideshape and support to the wound covering region 500. The edge region 510can include, for example, an adhesive configured to attach the edgeregion 510 to a surface of a body part in an area adjacent to a wound.The edge region 510 can include, for example, a cover configured to sealthe edge region 510 and the adjacent body part surface from substancesmoving between the edge region 510 and the adjacent body part surface.For example, the edge region 510 can include a cover configured toprevent wetness, debris, dirt or microbial agents from travellingbetween the edge region 510 and the body surface.

FIG. 5 illustrates an appurtenance 120 affixed to a wound dressing toform a wound dressing-appurtenance combination unit 125. Theappurtenance 120 includes a substrate 585 configured to attach to thewound dressing 500, 510. The appurtenance 120 includes a fluid-activatedvoltaic cell 560 attached to the substrate 585. The appurtenance 120includes a transmission unit 580 attached to a surface of the substrate585, the transmission unit 580 including circuitry 530 and an antenna520. The transmission unit 580 is configured to transmit a signal inresponse to current generated by the fluid-activated voltaic cell 560.The fluid-activated voltaic cell 560 is electrically connected to thetransmission unit 580 with a wire connector 595. The appurtenance 120includes a projection 200 operably attached to the fluid-activatedvoltaic cell 560. The projection 200 is of a size and shape to extendinto an interior region of the wound dressing 500, 510 (not depicted inFIG. 5 for purposes of illustration of the structure of the appurtenance120, but see FIG. 2B). The projection 200 is configured to sample afluid within an interior region of the wound dressing 500, 510. Forexample, the projection 200 includes an opening 590 at the end of theprojection 200 distal to the end of the projection 200 adjacent to thesubstrate 585, the opening 590 configured to allow fluid flow from aninterior region of the wound dressing 500, 510 into the interior region575 of the fluid-activated voltaic cell 560.

As shown in FIG. 5, an appurtenance 120 affixed to a wound dressing toform a wound dressing—appurtenance combination unit 125 includes asubstrate 585. The substrate 585 can include, for example, a flexibleplastic, which can be configured in a thin film or as a mesh of no morethan a few millimeters (mm) in thickness. For example, the substrate 585can be no more than 3 mm, or no more than 5 mm, thick depending on theembodiment. The substrate 585 can include, for example, a flexible papermaterial. The substrate 585 can include, for example, a compositematerial. The substrate 585 can include, for example, one or morematerials with properties such as durability, strength, cost, weight,bio-compatibility and disposability that are suitable for a givenembodiment. As illustrated in FIG. 5, the substrate 585 is configured toirreversibly attach to the wound covering region 500 of the wounddressing. For example, the substrate 585 can include an adhesivematerial on a face configured to conform to a surface of the wounddressing 500. For example, the substrate 585 can include one or morebarbs, hooks or other projections on the face configured to conform tothe surface of the wound dressing 500.

FIG. 5 depicts a fluid-activated voltaic cell 560 attached to thesubstrate 585. As described herein, a “fluid-activated voltaic cell” isan electrochemical cell that is configured to derive electrical energyfrom a spontaneous oxidation-reduction (redox) reaction that takes placewithin the cell when fluid is present within the cell. A fluid-activatedvoltaic cell includes at least two electrodes joined by an electricalconnector. The electrodes are located within an interior region of thefluid-activated voltaic cell. The electrodes are positioned with a spaceor a gap between the electrodes. When fluid from a wound dressing ispresent in the space, one electrode will be reduced and the other willbe oxidized by contact with the fluid, which serves as an electrolyte.As shown in FIG. 5, the fluid-activated voltaic cell 560 includes afirst electrode 555 and a second electrode 565 separated by space in aninterior region 575. A first electrode 555 and a second electrode 565are fabricated from materials with different electrochemical properties,particularly different oxidation-reduction potentials. The materialsfabricating the electrodes can be selected for their oxidation-reductionpotentials in the presence of fluid. The materials fabricating two ormore electrodes can be selected for their oxidation-reduction potentialsin combination. For example, a first electrode can be fabricated fromcopper and a second electrode can be fabricated from lead. For example,a first electrode can be fabricated from zinc and a second electrode canbe fabricated from copper. For example, a first electrode can befabricated from copper and a second electrode can be fabricated fromiron. For example, a first electrode can be fabricated from zinc and asecond electrode can be fabricated from lead. For example, a firstelectrode can be fabricated from zinc and a second electrode can befabricated from nickel. It has been estimated that electrochemical cellsincluding different combinations of electrodes can produce voltages ofapproximately 0.5 V to approximately 1.7 V. See: Goodisman,“Observations on Lemon Cells,” Journal of Chemical Education, vol. 78,no. 4, 516-518 (2001); Lee et al., “Water Activated Disposable and LongShelf Life Microbatteries,” 16th IEEE Micro Electro Mechanical SystemsConference, Kyoto, 19-23 Jan. 2003; and Sammoura et al., “WaterActivated Disposable and Long Shelf Life Microbatteries,” Sensors andActuators A 111:79-86 (2004), which are each incorporated by referenceherein. As shown in FIG. 5, the interior region 575 of thefluid-activated voltaic cell 560 is positioned between the firstelectrode 555 and the second electrode 565 and configured to include aspace within the interior region 575 that can be occupied by fluid flowfrom the wound dressing. An electrical connector 505, such as a wire,joins to the first electrode 555 and the second electrode 565. In someembodiments, the fluid-activated voltaic cell 560 can include an anodeand a cathode. The first electrode 555 and the second electrode 565 arepositioned with the interior region 575 between them and configured sothat fluid from the wound dressing can flow into the interior region575.

Some embodiments include at least one enhancement unit 570 positionedadjacent to one or both of the first and second electrodes 555, 565within the fluid-activated voltaic cell 560. An “enhancement unit”includes at least one chemical enhancer of the spontaneous redoxreaction that takes place within the cell when fluid is present withinthe cell. The chemical enhancer promotes an electrochemical reactionwithin the fluid-activated voltaic cell 560. The chemical enhancer ofthe voltaic cell is configured to be released when it contacts the fluidfrom the wound dressing, such as wound-related liquids, including bloodand pus. In some embodiments, the enhancement unit includes at least onedry acid unit configured to release acid when contacted by a liquid. Forexample, the enhancement unit can include a dry or crystalline form ofan acid, such as citric acid or ascorbic acid.

Some embodiments include at least one desiccant unit within thefluid-activated voltaic cell 560. A “desiccant unit” includes one ormore desiccant agents packaged as appropriate for the agent andembodiment. For example, at least one desiccant unit can be configuredto reduce humidity within the interior region 575 of the fluid-activatedvoltaic cell 560. In some embodiments, at least one desiccant unit canbe configured to form a region of low humidity within the interiorregion 575 of the fluid-activated voltaic cell 560. In some embodiments,at least one desiccant unit can be configured to encourage fluid flowinto a region of low humidity within the interior region 575 of thefluid-activated voltaic cell 560 from a region of higher humidity, suchas the interior of a moist wound dressing. In some embodiments, at leastone desiccant unit can be configured to maintain a region of lowhumidity within the interior region 575 of the fluid-activated voltaiccell 560 during transport or storage of the appurtenance. For example,the at least one desiccant unit can be configured to maintain relativelylow humidity within at least one enhancement unit 570 positionedadjacent to one or both of the first and second electrodes 555, 565within the fluid-activated voltaic cell 560 prior to use of theappurtenance. A desiccant unit can be configured to produce a humiditygradient between a relatively humid interior of a moist wound dressingand a relatively dry interior region 575 of the fluid-activated voltaiccell 560. Such a humidity gradient can encourage fluid flow into thefluid-activated voltaic cell 560 when sufficient fluid is present withinthe attached wound dressing.

Some embodiments include at least one humectant unit within thefluid-activated voltaic cell 560. A “humectant unit” includes one ormore desiccant agents packaged as appropriate for the agent andembodiment. In some embodiments, at least one humectant unit can beconfigured to encourage fluid flow into a region of low humidity withinthe interior region 575 of the fluid-activated voltaic cell 560 from aregion of higher humidity, such as the interior of a moist wounddressing. A humectant unit can be configured to produce a humiditygradient between the interior of a moist wound dressing and the interiorregion 575 of the fluid-activated voltaic cell 560. Such a humiditygradient can encourage fluid flow into the fluid-activated voltaic cell560 when sufficient fluid is present within the attached wound dressing.

Also as illustrated in FIG. 5, the appurtenance 120 affixed to a wounddressing to form a wound dressing-appurtenance combination unit 125includes a transmission unit 580 attached to a surface of the substrate.The transmission unit 580 includes circuitry 530 and at least oneantenna 520. Although the transmission unit 580 is illustrated asvisible in FIG. 5, in some embodiments all or part of the transmissionunit 580 will be covered and not be visible. For example, thetransmission unit 580 may be under a cover (e.g. 240 as illustrated inFIGS. 2A, 2B, 3A and 3B).

The transmission unit 580 is configured to transmit a signal in responseto power generated by the fluid-activated voltaic cell 560. Thetransmission unit 580 is configured to transmit a signal utilizing thepower generated by the fluid-activated voltaic cell 560. Thetransmission unit 580 can be configured to respond to activation of thefluid-activated voltaic cell 560. The transmission unit 580 can beconfigured to transmit a signal in response to a current generated bythe fluid-activated voltaic cell 560. The transmission unit 580 can beconfigured to transmit a signal in response to a voltage generated bythe fluid-activated voltaic cell 560. The transmission unit 580 can beconfigured to transmit a signal in response to a voltage and a currentgenerated by the fluid-activated voltaic cell 560. Electrical power,including current and voltage, generated by the redox reaction in thefluid-activated voltaic cell 560 powers signal transmission from thetransmission unit 580. One or more connectors 595, such as wire,electrically connects the transmission unit 580 and the fluid-activatedvoltaic cell 560.

In some embodiments, a converter can be operably connected between thetransmission unit 580 and the fluid-activated voltaic cell 560,connected with the one or more connectors 595. In some embodiments, acurrent to voltage boost converter can be included along the connector595 between the transmission unit 580 and the fluid-activated voltaiccell 560. In some embodiments, a current to voltage step-up convertercan be included along the connector 595 between the transmission unit580 and the fluid-activated voltaic cell 560. A converter can beoperably attached to the fluid-activated voltaic cell 560 and to thetransmission unit 580 with one or more connectors 595.

As illustrated in FIG. 5, an antenna 520 can be a substantially planarantenna, such as commonly used in radio frequency identification (RFID)or near field communication (NFC) units. The transmission unit 580 caninclude a RFID unit. The transmission unit 580 can include a NFC unit.The transmission unit 580 can include a unique identifier, such as aRFID identifier, to specify a specific transmission unit 580. Prior touse, the antenna 520 can be detuned with a removable surface layer of aconductive material. This can be desirable to reduce excess RFIDsignals, for example from appurtenances 120 in storage prior toattachment to a wound dressing. See U.S. Pat. No. 7,724,136 toPosamentier, titled “Revealable RFID Devices,” which is incorporatedherein by reference. The circuitry 530 of the transmission unit 580 caninclude a variety of components, as desired in a particular embodiment.The circuitry 530 of the transmission unit 580 can include a processor535. The circuitry 530 can include non-volatile memory 550. Thecircuitry 530 can include a transmitter 540. The circuitry 530 caninclude one or more additional modules 545. For example, the circuitry530 can include a receiver. For example, the circuitry 530 can include atransceiver. For example, the circuitry 530 can include an additionalantenna. For example, the circuitry 530 can include volatile memory. Forexample, the circuitry 530 can include non-volatile memory. Thecircuitry 530 can include dielectric material configured to electricallyinteract with one or more antennas. See, for example, U.S. Pat. No.7,055,754 to Forester, titled “Self-Compensating Antennas for SubstratesHaving Differing Dielectric Constant Values,” which is incorporatedherein by reference.

A transmission unit 580 can be configured to transmit a signal inresponse to an interrogation signal. A transmission unit 580 can includean energy harvesting unit, such as a unit configured to obtain energyfrom electromagnetic waves. A transmission unit 580 can include atransponder utilizing electromagnetic waves, for example as described in“Fundamental Operating Principles,” in Chapter 3 of the RFID Handbook:Fundamentals and Applications in Contactless Smart Cards andIdentification, Klaus Finkenzeller, John Wiley & Sons, (2003), which isincorporated herein by reference. A transmission unit 580 can include anoscillator and encoder configured to generate a programmable pulseposition-modulated signal in the radio frequency range. See, forexample, U.S. Pat. No. 4,384,288 to Walton, titled “Portable RadioFrequency Emitting Identifier,” which is incorporated herein byreference. A transmission unit 580 can include a radio frequencyidentification device (RFID). A transmission unit 580 can be configuredto be a transmitter of signals in the UHF range. A transmission unit 580including an RFID device can be configured to transmit signals in theUHF standard range utilized in a global region, as illustrated in the“Worldwide RFID UHF Map” by Intelleflex Corporation (©2009), which isincorporated herein by reference. A transmission unit 580 can include aradio frequency identification device (RFID). See, for example, Chawlaand Ha, “An Overview of Passive RFID,” IEEE Applications and Practice,11-17 (September 2007), which is incorporated herein by reference. Atransmission unit 580 can include a battery-assisted passive RFIDdevice, such as sold by Alien Technology®, Morgan Hill, Calif., such asdescribed in the brochure from Alien Technology® titled “BatteryAssisted Passive Tags” and incorporated herein by reference. Atransmission unit 580 can include an optical transmitter unit. Atransmitter unit can be configured to transmit at approximately 13.56megahertz (MHz), or within the ISO 14443 standard parameters. SeePatauner et al., “High Speed RFID/NFC at the Frequency of 13.56 MHz,”presented at the First International EURASIP Workshop on RFIDTechnology, pages 1-4, 24-25 Sep. 2007, Vienna Austria, which isincorporated herein by reference. A transmission unit 580 can include atleast two antennas. A transmission unit 580 can include aself-compensating antenna system. An antenna can include dielectricmaterial configured to electrically interact with one or more antennas.See, for example, U.S. Pat. No. 7,055,754 to Forester, titled“Self-Compensating Antennas for Substrates Having Differing DielectricConstant Values,” which is incorporated herein by reference. Atransmission unit 580 can include a hybrid backscatter system configuredto function in an RFID, IEEE 802.11x standard and Bluetooth system. See,for example, U.S. Pat. No. 7,215,976 to Brideglall, titled “RFID Device,System and Method of Operation Including a Hybrid backscatter-based RFIDProtocol Compatible with RFID, Bluetooth and/or IEEE 802.11xInfrastructure,” which is incorporated herein by reference. Atransmission unit 580 can be configured to transmit at approximately 131kilohertz (KHz), for example as part of a RuBee™ (IEEE standard 1902.1)system (sold, for example, by Visible Assets™, Inc.). See for example:the description of RuBee™ systems from the Visible Assets™ webpage;Stevens et al., “RuBee (IEEE 1902.1)—The Physics Behind, Real-Time, HighSecurity Wireless Asset Visibility Networks in Harsh Environments,” awhite paper from Visible Assets™; and in US Patent Application No.2007/0171076 to Stevens and Waterhouse, titled “Low-frequency Radio TagEncapsulating System,” each of which are incorporated herein byreference. A transmission unit 580 can include a near fieldcommunication (NFC) device. A transmission unit 580 can include aWireless Identification and Sensing Platform (WISP) device, manufacturedby Intel Corporation, such as described in the “WISP: WirelessIdentification and Sensing Platform” webpage (downloaded on Oct. 28,2011) incorporated herein by reference. A transmission unit 580 can beoperably coupled to a sensor, such as a sensor that detects changes incapacitance (see, e.g. Sample et al., “A Capacitive Touch Interface forPassive RFID Tags,” 2009 IEEE International Conference on RFID, 103-109(2009), which is incorporated herein by reference).

In some embodiments, the transmission unit 580 can include a pressuresensitive activation region, wherein the pressure sensitive activationregion is configured to be activated by physical pressure between asurface of the substrate 585 and a surface of the wound dressing (e.g.surface 410 as illustrated in FIG. 4). In some embodiments, thetransmission unit 580 can include a pressure sensitive activationregion, wherein the pressure sensitive activation region is configuredto be activated by physical pressure on a surface of the appurtenance120. See, for example, U.S. Pat. Nos. 6,693,513 and 6,037,879 to Tuttle,titled “Wireless Identification Device, RFID Device withPush-On/Push-Off Switch, and Method of Manufacturing WirelessIdentification Device,” and U.S. Pat. No. 6,863,220 to Selker, titled“Manually Operated Switch for Enabling and Disabling an RFID Card,” aswell as Sample et al., “A Capacitive Touch Interface for Passive RFIDTags,” 2009 IEEE International Conference on RFID, 103-109 (2009), whichare each incorporated herein by reference. A transmission unit 580 canbe operably coupled to a data storage unit, for example as described inU.S. Pat. No. 7,825,776 to Smith and Haehnel, titled “DeviceConfiguration with RFID,” and US Patent Application No. 2009/0243813 toSmith et al., titled “Wireless Programming of Non-Volatile Memory withNear-Field UHF Coupling,” which are each incorporated herein byreference.

In some embodiments, the transmission unit 580 can include an acoustictransmitter. For example, a transmission unit 580 can include apiezoelectric speaker. A variety of suitable piezoelectric speakers areavailable, including from Murata Manufacturing Co., Ltd., with NorthAmerican corporate headquarters in Smyrna, Ga. (see, e.g. the Muratacatalog titled “Piezoelectric Sounds Components” labeled P37E and datedJan. 28, 2010, which is incorporated herein by reference). Someembodiments can include acoustic transmitter units such as thosemanufactured by Advanced Telemetry Systems (headquartered in Isanti,Minn.) for the Pacific Northwest National Laboratory (see, e.g. JSATSAcoustic Transmitter information sheet from the Pacific NorthwestNational Laboratory, updated March 2010, which is incorporated herein byreference). In some embodiments, an appurtenance can include apiezoelectric speaker configured as part of an acoustic transmitter andalso to act as a signaling device (e.g. to generate a beeping noise inresponse to a signal from the processor).

In some embodiments, the transmission unit 580 can include an ultrasonictransmitter. In some embodiments, the transmission unit 580 can includean ultrasonic transducer. Multiple examples of ultrasonic transmittersand transducers are commercially available, often marketed under theterm “ultrasonic sensors” as it is used in the industry (see, e.g. theMurata catalog titled “Ultrasonic Sensor” labeled 515E and dated Oct.31, 2008, which is incorporated herein by reference). The transmitterunit can be configured as part of an ultrasonic ranging system. See:Wang, “A Design Method of Ultrasonic Ranging System with High Accuracy,”Journal of Computational Information Systems, 7: 7 pages 2444-2451(2011), which is incorporated herein by reference. The transmission unit580 can be configured to communicate with an ultrasonic communicationsystem. See: Chen and Wu, “Ultrasonic System with Infrared CommunicationTechnology,” Journal of Computers, vol. 6, no. 11, pages 2468-2475(2011), which is incorporated herein by reference.

In some embodiments, the transmission unit 580 can include an opticaltransmitter. For example, an optical transmitter unit can include one ormore light emitting diodes (LEDs). For example, an optical transmitterunit can include an infrared laser. In some embodiments, opticaltransmitter units can be desirable to minimize interference from nearbyelectrical equipment, such as medical equipment. See: Kavehrad,“Sustainable Energy-Efficient Wireless Applications Using Light,” IEEECommunications Magazine, vol. 48, no. 12, pages 66-73, (2010); andFadlullah and Kavehrad, “Indoor High-Bandwidth Optical Wireless Linksfor Sensor Networks” Journal of Lightwave Technology, vol. 28, no. 21,pages 3086-3094 (2010), which are incorporated herein by reference.

Some embodiments can include one or more additional transmission unitsdistinct from the transmission unit 580 attached to the fluid-activatedvoltaic cell 560. An additional transmission unit can be configured toutilize received signals as an energy source. For example, an additionaltransmission unit can include a passive RFID unit. An additionaltransmission unit can include an attached power source, such as abattery. For example, an additional transmission unit can include, forexample, an active RFID unit and an attached thin-film battery. Anadditional transmission unit including an RFID unit can be included, forexample, as part of an inventory control device included with theappurtenance. An additional transmission unit including an RFID unit canbe included, for example, as part of a patient identification system,such as implemented in a hospital or care facility. An additionaltransmission unit can be, for example, an optical energy emitter, suchas an LED or other light emitting device. An additional transmissionunit can be, for example, an auditory emitter, such as a piezoelectricspeaker or other sound emitter. An additional transmission unit can be,for example, a vibration emitter, such as a piezoelectric device.

FIG. 5 illustrates that the appurtenance 120 affixed to a wound dressingto form a wound dressing-appurtenance combination unit 125 includes aprojection 200. Although the projection 200 is displayed for thepurposes of illustration, when an appurtenance 120 is affixed to a wounddressing to form a wound dressing-appurtenance combination unit 125 innormal use, the projection 200 would extend into an interior region ofthe wound dressing (see, e.g. FIG. 2B), and, therefore, not be visiblefrom a superficial view. The projection 200 is configured to allow fluidflow from an interior region of the wound dressing into an interiorregion of the appurtenance 120. As illustrated in FIG. 5, in someembodiments the projection 200 can include a substantially hollowtubular structure. The projection 200 can be a substantially hollowtubular structure with an opening 590 at the end distal to theappurtenance. The projection 200 can be of a size and shape to projectunderneath one or more superficial structures of the wound dressing whenthe wound dressing is in use. The projection 200 can be of a size andshape to project through a width of the wound dressing when theappurtenance is attached to the wound dressing. In some embodiments, theprojection 200 is fabricated from a plastic material. For example, theprojection 200 can be fabricated from a pliable plastic material. Forexample, the projection 200 can be fabricated from a bio-compatibleplastic material. For example, the projection 200 can be fabricated froma plastic material that can be sterilized prior to use of theappurtenance 120. The projection 200 illustrated in FIG. 5 includes anopening 590 at the end of the projection 200 distal to the end of theprojection 200 adjacent to the substrate 585. The projection 200 can beof a size and shape to project from the outer surface of the wounddressing to within layers of the wound dressing. FIG. 5 depicts afluid-activated voltaic cell 560 attached to the projection 200. Thefluid-activated voltaic cell 560 includes an internal region 575. Theprojection 200 is configured to allow fluid flow from the interior ofthe wound dressing 500 through the opening 590 of the projection 200into the internal region 575 of the fluid-activated voltaic cell 560.The projection 200 illustrated in FIG. 5 includes a substantially hollowtube with a first aperture 590 at a location adjacent to the interiorregion of the wound dressing and a second aperture at a locationadjacent to the surface of the fluid-activated voltaic cell 560. In someembodiments, there are a plurality of projections 200.

The wound dressing-appurtenance combination unit 125 is configured sothat fluid from an interior region of a wound dressing can flow into theprojection 200 through the opening 590. Such fluid flow can occur, forexample, when the wound dressing includes excessive levels of woundfluid (e.g. blood, pus) that moves into the projection 200 through theopening 590 from capillary action or in response to a pressuredifference between the interior of the wound dressing and the interiorof the projection and the internal region 575 of the fluid-activatedvoltaic cell 560. The fluid-activated voltaic cell 560 can include achamber attached to a conduit, wherein the chamber is configured toreceive the fluid from the external region. The fluid within theinterior region 575 of the fluid-activated voltaic cell 560 serves as anelectrolyte and activates the redox reaction of the electrodes 555, 565.The resulting current powers the transmission unit 580 and initiates thesending of a signal from the transmission unit 580. No electrical powerfrom the redox reaction of the electrodes 555, 565 need be stored by thesystem, such as in the circuitry 530. The current from the redoxreaction of the electrodes 555, 565 directly powers the transmissionunit 580 at the same time as the redox reaction is occurring. It isexpected that the current from the redox reaction of the electrodes 555,565 will last for a brief time, on the order of minutes, and the signaltransmitted from the transmission unit 580 will similarly occur for abrief time. Therefore, the wound dressing-appurtenance combination unit125 will generate a real-time signal that a wound dressing has excessiveinternal fluid, and therefore that it should be checked by a caregiver.In some embodiments, the signal from the wound dressing-appurtenancecombination unit 125 is received by an external device that containsmemory, and therefore can maintain a persistent indicator that the wounddressing requires attention. See, e.g. FIGS. 12 and 13 and associatedtext.

Some embodiments include a sensor. A sensor can be operably attached,for example, to a projection 200. A sensor can be operably attached, forexample, to a transmission unit 580. A transmitter unit 580 can beoperably coupled to a sensor, such as a sensor that detects changes incapacitance (see, e.g. Sample et al., “A Capacitive Touch Interface forPassive RFID Tags,” 2009 IEEE International Conference on RFID, 103-109(2009), which is incorporated herein by reference). A transmitter unit580 can be operably coupled to a sensor, such as described in: Ruhanenet al., “Sensor-enabled RFID Tag and Handbook,” from Building RadioFrequency Identification for the Global Environment (2008); Sample etal., “Design of an RFID-Based Battery-Free Programmable SensingPlatform,” IEEE Transactions on Instrumentation and Measurement, vol.57, no. 11, 2608-2615 (2008); Yeager et al., “Wirelessly-Charged UHFTags for Sensor Data Collection,” 2008 IEEE International Conference onRFID, Apr. 16-17, 2008, pages 320-327; U.S. Pat. Nos. 5,904,671 and6,348,640 to Navot and Botton, each titled “Tampon Wetness DetectionSystem;” U.S. Pat. No. 7,446,660 to Posamentier titled “PassiveEnvironmental RFID Transceiver;” and U.S. Pat. No. 5,704,352 to Tremblayand Buckles, titled “Implantable Passive Bio-Sensor,” which are eachincorporated herein by reference. A sensor can be operably attached, forexample, to a substrate 585. A sensor can be operably attached, forexample, to a fluid-activated voltaic cell 560. “Sensors,” as usedherein, can be of a variety of types depending on the embodiment. One ormore sensors can include at least one sensor responsive to changes incapacitance, or a measure of the ability of a configuration of materialsto store electric charge. A general review of biosensors that detectchanges in the dielectric properties of an electrode surface can befound in Berggren et al., “Capacitive Biosensors,” Electroanalysis vol.13, no. 3, 173-180, (2001), which is incorporated herein by reference.For example, one or more sensors can include a micromechanical biosensorwith a fixed-fixed beam attached to an interdigitated capacitor (see,for example, Lim et al., “A Micromechanical Biosensor withInterdigitated Capacitor Readout,” Proceedings of the 2011 IEEE/ICMEInternational Conference on Complex Medical Engineering, May 22-25,Harbin, China, which is incorporated herein by reference). Sensors canalso include nanowire nanosensors, for example as described in Cui etal., “Nanowire Nanosensors for Highly Sensitive and Selective Detectionof Biological and Chemical Species,” Science, vol. 293, 1289-1292(2001), which is incorporated herein by reference. Sensors can includethose utilizing antibodies secured to a graphene substrate. See Tehraniet al., “Detection of Monoclonal Antibodies using Chemically ModifiedGraphite Substances,” IEEE Sensors 2010 Conference Proceedings, 428-431,(2010), which is incorporated herein by reference. In some embodiments,sensors include aptamer-modified graphene field-effect transistors, seeOhno et al., “Graphene Field-Effect Transistors for Label-FreeBiological Sensors,” IEEE Sensors 2010 Conference Proceedings, 903-906,(2010), which is incorporated herein by reference. A sensor in anappurtenance can interact with a sensor present in a wound dressing, forexample as described in U.S. Pat. No. 6,283,938 to McConnell, titled“Medicating Bandage and Controllable Permeable Membrane,” which isincorporated herein by reference. A sensor can include a field effecttransistor (FET), such as described in U.S. Pat. No. 7,507,675 toZuilhof et al., titled “Device Manufacturing Method and Device,” whichis incorporated herein by reference. A sensor can include anano-cantilever device, such as described in U.S. Pat. No. 7,612,424 toEspinosa and Ke, titled “Nanoelectromechanical Bistable CantileverDevice,” which is incorporated herein by reference. A sensor can beconfigured to provide information regarding the wound dressing andassociated fluid, such as temperature, presence of specific analytes inthe fluid, or relative wetness of the dressing as a whole. A variety ofsensors can be utilized in different embodiments of the appurtenances,depending on factors such as the intended use of the appurtenance, size,weight, cost, bio-compatibility, safety and ease of disposal.

FIG. 6 depicts a wound dressing-appurtenance combination unit 125. Thewound dressing-appurtenance combination unit 125 of FIG. 6 is shown in a“top-down,” external view, similar to that of FIG. 5. As illustrated inFIG. 6, the wound dressing-appurtenance combination unit 125 includes awound dressing with a wound covering region 500 and an edge region 510.The appurtenance 120 includes a substrate 585. The appurtenance 120includes a transmission unit 580. The transmission unit 580 includes anantenna 520 and circuitry 530. A connector 595 is configured to providean electrical connection between the transmission unit 580 and afluid-activated voltaic cell 560. The connector 595 is configured toprovide electrical current to the transmission unit 580 from thefluid-activated voltaic cell 560. The fluid-activated voltaic cell 560includes a first electrode 555 and a second electrode 565 joined with anelectrical connector 505, such as a wire. The electrical connector 505is joined to the connector 595 to provide an electrical connectionbetween the transmission unit 580 and the fluid-activated voltaic cell560. The fluid-activated voltaic cell 560 includes an internal region575 between the first electrode 555 and a second electrode 565, theinternal region 575 configured to accept fluid flow through theprojection 200. The fluid-activated voltaic cell 560 includes twoenhancement units 570 positioned adjacent to each of the first electrode555 and a second electrode 565.

The projection 200 shown in FIG. 6 includes a plurality of apertures 590A, B, C located along the length of the projection 200. Each of theapertures 590 A, B, C will be positioned adjacent to a distinct regionof the interior of the wound dressing when the projection 200 isinserted within the wound dressing (not shown in FIG. 6 for purposes ofillustration). Each of the apertures 590 A, B, C is connected to aconduit 600 A, B, C within the projection 200. Each conduit 600 A, B, Cincludes a first end attached to an aperture 590 A, B, C and a secondend attached to the fluid activated voltaic cell 560. Each of theconduits 600 A, B, C is configured to direct fluid from the interiorregion of the wound dressing into the interior region 575 of thefluid-activated voltaic cell 560. As shown in FIG. 6, each of theconduits 600 A, B, C projects into the interior region 575 of thefluid-activated voltaic cell 560. In some embodiments, the projection200 is partially positioned within the fluid-activated voltaic cell 560and the projection 200 includes an aperture within the fluid-activatedvoltaic cell 560. Also as illustrated in FIG. 6, in some embodiments theprojection 200 includes a region 610 configured to facilitate insertionof the projection 200 into the wound dressing 500. For example, theprojection 200 can include a region 610 configured as a tapered point onthe distal end of the projection 200.

Some embodiments include a passive RFID unit including an identifier. Insome embodiments, the passive RFID unit can be integrated into thetransmission unit 580. In some embodiments, the passive RFID unit can bea distinct unit of the appurtenance 120. The passive RFID can beconfigured, for example, as an positioning control unit to confirm thepresence of the appurtenance 120 in a specific location, such as inassociation with a specific patient or wound dressing.

FIG. 7 illustrates aspects of an embodiment of an appurtenance 120, suchas that depicted in FIGS. 3A and 3B. The appurtenance 120 depicted in across-sectional view in FIG. 7 includes an enclosure 700 of a height andwidth to fit substantially within an interior region of a wound dressing(see, e.g. FIG. 3B). The appurtenance 120 depicted in a cross-sectionalview in FIG. 7 includes an enclosure 700 of a height and width to fitsubstantially within an interior region of a wound dressing, theenclosure 700 including at least one aperture 710 A, B configured toallow fluid to flow from the interior region of the wound dressing intothe enclosure 700 (see dotted arrows). The appurtenance 120 depicted inFIG. 7 also includes a fluid-activated voltaic cell 560 attached to oneor more of the at least one aperture 710 A, B. The appurtenance 120shown in FIG. 7 includes a transmission unit 580 attached to an internalsurface of the enclosure 700, the transmission unit 580 includingcircuitry 530 and at least one antenna 530, the transmission unit 580configured to transmit a signal in response to the fluid-activatedvoltaic cell 560. A wire connector 595 connects the transmission unit580 to the fluid-activated voltaic cell 560, the wire connector 595configured to conduct current from the fluid-activated voltaic cell 560to the transmission unit 580. Some embodiments can include a passiveRFID unit, including an identifier. The appurtenance 120 illustrated inFIG. 7 includes an enclosure 700 with substantially vertical wallstapering to an aperture 710 A at a position corresponding to an interiorregion of a wound dressing when the appurtenance 120 is in use. Afluid-activated voltaic cell 560 is positioned within the enclosure 700adjacent to the aperture 710 A. The fluid-activated voltaic cell 560includes an opening 720 A adjacent to the aperture 710 A of theenclosure 700. As shown in FIG. 7, in some embodiments an enclosure 700includes a plurality of apertures 710 A, 710 B. FIG. 7 illustrates asecond aperture 710 B in the wall of the enclosure 700, the secondaperture 710 B connected to a conduit 730. The conduit 730 is connectedto an opening 720 B in the fluid-activated voltaic cell 560 at an end ofthe conduit 730 distal to the second aperture 710 B.

Some embodiments include a microcapillary film within at least oneaperture 710 A, 710 B, the microcapillary film configured to directfluid from an interior region of the wound dressing into the interior ofthe enclosure 700. See, for example, U.S. Pat. No. 6,420,622 toJohnston, “Medical Article Having Fluid Control Film,” which isincorporated by reference herein. Some embodiments include a porous filmor mesh within at least one aperture 710 A, 710 B, configured to allowfluid flow from an interior region of the wound dressing into theinterior of the enclosure 700 and to minimize other matter entering theappurtenance (e.g. structural portion of the wound dressing or wounddebris).

The enclosure 700 depicted in FIG. 7 is a vertical, cross sectional viewof a substantially cone shaped enclosure 700. As shown in FIGS. 3A, 3Band 7, in some embodiments the enclosure 700 is a substantiallycylindrical structure, wherein the largest width of the substantiallycylindrical structure is less than the smallest width of the wounddressing. In some embodiments, the enclosure 700 is a substantiallypyramidal structure, wherein the largest width of the substantiallypyramidal structure is less than the smallest width of the wounddressing. In some embodiments, the enclosure 700 includes asubstantially conical or a substantially conical frustum shapedstructure. In some embodiments, the enclosure 700 includes across-sectional view square area (i.e. substantially at right angles tothe view illustrated in FIG. 7) that is substantially equal to or lessthan one tenth of a square area of a largest surface of the wounddressing. As shown in FIG. 7, the enclosure 700 includes one or moreflanges 730 at the upper edge of the substantially conical structure ofthe enclosure 700. The flanges 730 are positioned to locate theenclosure 700 relative to an outer surface of a wound dressing, and canbe positioned to provide a surface for attachment of a cover 240 (see,e.g. FIG. 3B). A flange 730 can include a flange region configured tocover part of an outer surface of the wound dressing when theappurtenance 120 is positioned for use with the wound dressing. One ormore flanges 730 can be located on the enclosure 700 in a manner tofunctionally inhibit the movement of the enclosure 700 into the interiorof the wound dressing layer. The one or more flanges 730 can be locatedon the enclosure 700 in a manner to expand a portion of thecircumference of the enclosure 700 and prevent the appurtenance 120 frommoving into the wound dressing beyond that expanded circumference. Theenclosure 700 can include one or more barbs positioned to hold theappurtenance 120 in place relative to the affixed wound dressing and toprevent the appurtenance 120 from slipping relative to the wounddressing. In some embodiments, the enclosure 700 includes one or morewalls, the walls forming a flange 730 on an edge of the enclosure 700,the flange 730 positioned to attach a fastener between a surface of thewound dressing and the enclosure 700. In some embodiments, the enclosure700 includes one or more walls, the walls forming a flange 730 on anedge of the enclosure 700, the flange 730 including one or moreprojections from a surface of the flange 730, the one or moreprojections positioned to pierce an outer surface of a wound dressing.For example, one or more flanges 730 can include one or more barbs,points or projections positioned to pierce an outer surface of a wounddressing and assist in maintaining the position of the appurtenancerelative to the wound dressing. In some embodiments, an enclosure 700can be formed as a substantially hollow tube.

Depending on the embodiment, the enclosure 700 of the appurtenance 120can be fabricated from a variety of materials. For example, theenclosure 700 of the appurtenance 120 can be fabricated from at leastone plastic material. For example, the enclosure 700 of the appurtenance120 can be fabricated from bio-compatible materials. In someembodiments, the enclosure 700 of the appurtenance 120 can be covered orcoated to increase functionality. For example, the enclosure 700 of theappurtenance 120 can be covered with bio-compatible materials on anexternal surface of the enclosure 700. For example, the enclosure 700 ofthe appurtenance 120 can be covered with a textured material to reducepotential slippage of the enclosure 700 within a wound dressing (seeFIG. 3B).

Some embodiments include a fastener configured to form a seal between anedge of an enclosure 700 and a surface of a wound dressing. For example,an edge of an enclosure 700 can include an adhesive configured to sealthe edge of the enclosure 700 to a surface of the wound dressing. Forexample, as illustrated in FIG. 7, the fastener can include asubstantially planar cover 240 with an upper surface and a lowersurface, the lower surface conforming to both the edge of the enclosure700 and to the surface of the wound dressing, and adhesive on at least aportion of the substantially planar cover 240. Some embodiments includea piercing region operably attached to an edge of the enclosure 700distal to an edge of the enclosure 700 adjacent to an outer surface ofthe wound dressing when the appurtenance is positioned for use with thewound dressing. For example, the enclosure 700 can include a tip, point,edge or surface projection configured to pierce a wound dressing surfacewhen the appurtenance is affixed to the wound dressing.

FIG. 7 also includes a fluid-activated voltaic cell 560 attached to bothof the apertures 710 A, 710 B in the enclosure 700. The fluid-activatedvoltaic cell 560 includes two electrodes 555, 565, electricallyconnected with a wire connection 505. The first electrode 555 and thesecond electrode 565 are positioned with an interior region 575 of thefluid-activated voltaic cell 560 between them. In some embodiments, thefluid-activated voltaic cell 560 includes at least one anode and atleast one cathode. In some embodiments, the fluid-activated voltaic cell560 includes at least one enhancement unit 570, the enhancement unit 570configured to release at least one chemical enhancer of anelectrochemical reaction within the fluid-activated voltaic cell 560 inresponse to contact with a fluid. In some embodiments, the at least oneenhancement unit 570 includes at least one dry acid unit configured torelease acid when contacted by a liquid. The interior region 575 of thefluid-activated voltaic cell 560 is configured to receive fluid flowthrough the aperture 710 A, B (illustrated as dotted arrows in FIG. 7).In some embodiments, the fluid-activated voltaic cell 560 includes achamber configured to receive the fluid. As illustrated in FIG. 7, theapertures 710 A, 710 B can be oriented adjacent to different regions ofthe wound dressing when the appurtenance 120 is in place, and thereforeto sample any potential wound liquids present in the different regionsof the wound dressing.

In some embodiments with enclosures such as illustrated in FIG. 7, therecan be a second fluid-activated voltaic cell 560 attached to at leastone second aperture 710 B, the at least one second aperture 710 Bconfigured to allow fluid to flow from a second interior region of thewound dressing into an interior of the second fluid-activated voltaiccell 560. See also FIG. 8. Some embodiments can include a sensorattached to at least one aperture 710 A, 710 B of the enclosure 700, anda connection between the sensor and the transmission unit 580. Forexample, the sensor can be operably coupled to the electrochemicalcircuit formed by the fluid-activated voltaic cell 560 and thetransmission unit 580, so that the sensor is activated by current fromthe fluid-activated voltaic cell 560. For example, there may be a wireconnection between the sensor and the transmission unit 580.

FIG. 8 illustrates an appurtenance 120 attached to a wound dressing 500,510 and forming an appurtenance affixed to a wound dressing combinationunit, 125. The view of FIG. 8 is similar to those of FIGS. 5 and 6. Theappurtenance 120 shown in FIG. 8 includes a substrate 585. Theappurtenance 120 includes two projections 200 A, 200 B. The projections200 A, 200 B are positioned at different faces of the appurtenance 120.The projections 200 A, 200 B are of different lengths and project atdifferent angles (e.g. the angle shown as θ in FIGS. 2 A and 2 B) fromthe plane of the substrate 585 of the appurtenance 120. Each of theindividual projections 200 A, 200 B includes an opening 590 A, 590 B.Each of the openings 590 A, 590 B is positioned to be adjacent to adifferent region of the interior of the wound dressing 510. Theindividual projections 200 A, 200 B can, therefore, be considered to besampling different regions of the interior of the wound dressing 510when the appurtenance affixed to a wound dressing combination unit, 125is in use.

Some embodiments include a microcapillary film within at least oneopening 590 A, 590 B, the microcapillary film configured to direct fluidfrom an interior region of the wound dressing into the interior of theprojection 200. See, for example, U.S. Pat. No. 6,420,622 to Johnston,“Medical Article Having Fluid Control Film,” which is incorporated byreference herein. Some embodiments include a porous film or mesh withinat least one opening 590 A, 590 B, configured to allow fluid flow froman interior region of the wound dressing into the interior of theprojection 200 and to minimize other matter entering the appurtenance(e.g. structural portion of the wound dressing or wound debris).

Each of the projections 200 A, 200 B illustrated in FIG. 8 is operablyattached to a fluid-activated voltaic cell 560 A, 560 B. Each of thefluid-activated voltaic cells 560 A, 560 B includes a first electrode555 and a second electrode 565 connected with a wire connection 505.Each of the fluid-activated voltaic cells 560 A, 560 B includes aninterior region 575 between the first electrode 555 and the secondelectrode 565. Each of the fluid-activated voltaic cells 560 A, 560 Bincludes an enhancement unit 570 adjacent to each of the electrodes 555,565. A wire connector 595 couples the fluid-activated voltaic cells 560A, 560 B to a single transmission unit 580. The transmission unitincludes circuitry 530 and an antenna 520.

In the embodiment illustrated in FIG. 8, a fluid, such as blood or pus,present in the region of the wound dressing adjacent to either of therespective projection 200 A, 200 B openings 590 A, 590 B would flow intothe projection 200 A, 200 B through the respective opening 590 A, 590 B.The presence of liquid in the interior region 575 between the firstelectrode 555 and the second electrode 565 acts as an electrolyte forthe electrochemical reaction of the respective fluid-activated voltaiccell 560 A, 560 B. Current generated by the electrochemical reactionwould move through the wire connector 595 and into the transmission unit580, activating the transmission unit 580. Therefore, in theconformation illustrated in FIG. 8, excess liquid from the wounddressing in either the region of the wound dressing adjacent to eitherof the respective projection 200 A, 200 B openings 590 A, 590 B wouldinitiate the electrochemical reaction of the respective fluid-activatedvoltaic cell 560 A, 560 B, resulting in a signal being generated by thetransmission unit 580.

FIG. 9 illustrates an appurtenance 120 to a wound dressing. Theappurtenance 120 includes a substrate 585 and two projections, 200 A,200 B, projecting from different sides of the substrate 585. As in FIG.8, the embodiment illustrated in FIG. 9 includes projections, 200 A, 200B of different lengths and angles (e.g. the angle shown as θ in FIGS. 2A and 2 B) from the plane of the substrate 585 of the appurtenance 120.Therefore, the embodiment shown in FIG. 9 would sample fluid potentiallypresent in different regions of a wound dressing. The different regionsof a wound dressing can be vertically or horizontally in differentplanes of the wound dressing, or both. Each of the projections 200 A,200 B is connected to its respective fluid-activated voltaic cell 560 A,560 B. Each of the fluid-activated voltaic cells 560 A, 560 B includes afirst electrode 555 and a second electrode 565 connected with a wireconnection 505. Each of the fluid-activated voltaic cells 560 A, 560 Bincludes an interior region 575 between the first electrode 555 and thesecond electrode 565. Each of the fluid-activated voltaic cells 560 A,560 B includes an enhancement unit 570 adjacent to each of theelectrodes 555, 565. A wire connector 595 couples each of thefluid-activated voltaic cells 560 A, 560 B to a distinct transmissionunit 580 A, 580 B. Each of the respective transmission units 580 A, 580B includes circuitry 530 and an antenna 520. Each of the respectivetransmission units 580 A, 580 B is configured to transmit a signal inresponse to a current generated by a redox reaction in the attachedfluid-activated voltaic cell 560 A, 560 B.

In the embodiment illustrated in FIG. 9, a fluid, such as blood or pus,present in the region of the wound dressing adjacent to either of therespective projection 200 A, 200 B openings 590 A, 590 B would flow intothe projection 200 A, 200 B through the respective opening 590 A, 590 B.The presence of liquid in the interior region 575 between the firstelectrode 555 and the second electrode 565 acts as an electrolyte forthe electrochemical reaction of the respective fluid-activated voltaiccell 560 A, 560 B. Current generated by the electrochemical reactionwould move through the wire connector 595 and into the associatedtransmission unit 580 A, 580 B, activating the specific transmissionunit 580 A, 580 B. Therefore, in the conformation illustrated in FIG. 9,excess liquid from the wound dressing in either the region of the wounddressing adjacent to either of the respective projection 200 A, 200 Bopenings 590 A, 590 B would initiate the electrochemical reaction of therespective fluid-activated voltaic cell 560 A, 560 B, resulting in asignal being generated by the specific transmission unit 580 A, 580 B.In a system wherein a signal transmitted from a specific transmissionunit 580 A, 580 B could be distinguished from other potential signals,the region of the wound dressing from which the fluid was obtained canalso be associated with the specific signal. Such information can beuseful, for example, to specify the relative depth or width of the wounddressing where the fluid was present. Such information can be useful,for example, to specify if the fluid is widespread in the wound dressing(i.e. present in multiple locations).

FIG. 10 depicts an appurtenance 120 to a wound dressing. Theappurtenance 120 includes a substrate 585. As illustrated in FIG. 10,the appurtenance 120 includes a plurality of conduits 1000 A, B, C, D,E, F configured to direct fluid from a plurality of regions of a wounddressing adjacent to the appurtenance 120. Although the appurtenance 120is illustrated in FIG. 10 as substantially planar, in some embodimentsthe appurtenance can include other three dimensional structures, such ascones, ellipses, cylinders, or a combination of shapes.

An appurtenance 120 can include one or more surfaces configured to matewith one or more surfaces of a wound dressing (not illustrated in FIG.10). Each of the plurality of conduits 1000 A, B, C, D, E, F ispositioned to allow fluid from an adjacent region of a wound dressing toflow through the conduit 1000 A, B, C, D, E, F into the attachedfluid-activated voltaic cell 560 A, B, C, D, E, F. A conduit 1000 A, B,C, D, E, F can include features configured to encourage the flow offluid from an adjacent region of a wound dressing to flow through theconduit 1000 A, B, C, D, E, F. For example, a conduit 1000 A, B, C, D,E, F can include a plurality of microchannels configured to direct fluidflow from the exterior of the appurtenance 120 into the fluid-activatedvoltaic cell 560 A, B, C, D, E, F. See, for example, U.S. Pat. No.6,420,622 to Johnston, “Medical Article Having Fluid Control Film,”which is incorporated by reference herein. For example, one or more ofthe conduits 1000 A, B, C, D, E, F can include a projection extendinginto the region surrounding the appurtenance, the projection configuredto direct fluid flow from the exterior of the appurtenance 120 into thefluid-activated voltaic cell 560 A, B, C, D, E, F. No projections areillustrated in FIG. 10, however examples are, inter alia, in FIGS. 2A,2B, 5, 6, 8, 9 and 12. Each of the fluid-activated voltaic cells 560 A,B, C, D, E, F has an attached transmission unit 580 A, B, C, D, E, F.Each of the transmission units 580 A, B, C, D, E, F is configured totransmit a signal in response to current generated by the attachedfluid-activated voltaic cell 560 A, B, C, D, E, F. In some embodiments,each of the transmission units 580 A, B, C, D, E, F transmits a distinctsignal, i.e. a signal including a unique identifier of that transmissionunit 580 A, B, C, D, E, F. The respective location(s) in the wounddressing with fluid flowing into the conduits 1000 A, B, C, D, E, F can,therefore, be derived from the distinct signal from generated by each ofthe transmission units 580 A, B, C, D, E, F.

FIG. 11 depicts an appurtenance 120 to a wound dressing. Theappurtenance 120 includes a substrate 585. As illustrated in FIG. 11,the appurtenance 120 includes a plurality of conduits 1100 A, B, C, D,E, F configured to direct fluid from a plurality of regions of a wounddressing adjacent to the appurtenance 120. Although the appurtenance 120is illustrated in FIG. 11 as substantially planar, in some embodimentsthe appurtenance can include other three dimensional structures, whichcan include a combination of curvilinear structures. An appurtenance 120can include one or more surfaces configured to mate with one or moresurfaces of a wound dressing (not illustrated in FIG. 11). Each of theplurality of conduits 1100 A, B, C, D, E, F is positioned to allow fluidfrom an adjacent region of a wound dressing to flow through the conduit1100 A, B, C, D, E, F into the attached fluid-activated voltaic cell 560A, B, C, D, E, F. A conduit 1100 A, B, C, D, E, F can include featuresconfigured to encourage fluid from an adjacent region of a wounddressing to flow through the conduit 1100 A, B, C, D, E, F. For example,a conduit 1100 A, B, C, D, E, F can include a plurality of microchannelsconfigured to direct fluid flow from the exterior of the appurtenance120 into the fluid-activated voltaic cell 560 A, B, C, D, E, F. See, forexample, U.S. Pat. No. 6,420,622 to Johnston, “Medical Article HavingFluid Control Film,” which is incorporated by reference herein. Forexample, one or more of the conduits 1100 A, B, C, D, E, F can include aprojection extending into the region surrounding the appurtenance, theprojection configured to direct fluid flow from the exterior of theappurtenance 120 into the fluid-activated voltaic cell 560 A, B, C, D,E, F. No projections are illustrated in FIG. 11, however examples are,inter alia, shown in FIGS. 2A, 2B, 5, 6, 8, 9 and 12.

As illustrated in FIG. 11, each of the fluid-activated voltaic cells 560A, B, C, D, E, F is attached to a transmission unit 580 with a wireconnector 595 A, B, C, D, E, F. The transmission unit 580 includes anantenna 520 and circuitry 530. The transmission unit 580 is configuredto send a signal in response to a current transmitted through one ormore of the associated wire connectors 595 A, B, C, D, E, F from one ormore of the fluid-activated voltaic cells 560 A, B, C, D, E, F. Thetransmission unit 580 of the appurtenance 120 illustrated in FIG. 11 isconfigured to send a series of signals in response to current generatedby the fluid-activated voltaic cells 560 A, B, C, D, E, F in series. Forexample, the transmission unit 580 may be activated at a first time inresponse to a current generated by fluid-activated voltaic cell 560 Aand carried by the wire connector 595 A from the fluid-activated voltaiccell 560 A to the transmission unit 580. For example, the transmissionunit 580 may be activated at a second time in response to a currentgenerated by fluid-activated voltaic cell 560 B and carried by the wireconnector 595 B from the fluid-activated voltaic cell 560 B to thetransmission unit 580. For example, the transmission unit 580 may beactivated at a third time in response to a current generated byfluid-activated voltaic cell 560 C and carried by the wire connector 595C from the fluid-activated voltaic cell 560 C to the transmission unit580. The transmission unit 580 at further times can be activated by, forexample, in response to current generated by fluid-activated voltaiccells 560 D, E and F.

FIG. 12 illustrates an appurtenance 120 attached to a wound dressing 115to form a wound dressing with an affixed appurtenance combination unit125. The wound dressing with an affixed appurtenance combination unit125 shown in FIG. 12 is illustrated in cross-section, similar to theviews of FIGS. 2A and 2B. The wound dressing with an affixedappurtenance combination unit 125 includes a wound dressing portionincluding an outer layer 210 and a wound dressing layer 220. A cover 240further adheres to the outer surface of the outer layer 210 and to anouter surface of the appurtenance 120.

The appurtenance 120 includes a plurality of projections 200 A, B, C, Dand E. Each projection 200 A, B, C, D and E is configured to allow fluidflow from an adjacent region of the wound dressing interior, asillustrated by the dotted arrows. As shown in FIG. 12, the projections200 A, B, C, D and E are spaced apart, so that they extend fromdifferent positions on the appurtenance 120. In addition, theprojections 200 A, B, C, D and E are of different lengths. Theprojections 200 A, B, C, D and E also extend from the surface of theappurtenance at different angles, θ₁, θ₂, θ₃, θ₄, θ₅. The combination ofprojections 200 A, B, C, D and E spaced apart on the appurtenance 120,of different lengths and extending at different angles, θ₁, θ₂, θ₃, θ₄,θ₅ results in an appurtenance 120 that is configured to sample fluidfrom a significant portion of the interior of the appurtenance 120. Theconfiguration of projections 200 A, B, C, D and E spaced apart on theappurtenance 120, of different lengths and extending at differentangles, θ₁, θ₂, θ₃, θ₄, θ₅ results in an appurtenance 120 that cansample fluid present in different regions and layers of the wounddressing layer 220. The plurality of projections 200 A, B, C, D and Ecan each be attached to an individual fluid-activated voltaic cell whichare in turn connected to individual transmission units (e.g. asillustrated in FIG. 10). The plurality of projections 200 A, B, C, D andE can each be attached to an individual fluid-activated voltaic cellwhich are all connected to one transmission unit (e.g. as illustrated inFIG. 11). The plurality of projections 200 A, B, C, D and E can each beattached to a single fluid-activated voltaic cell connected to acorresponding transmission unit (see FIG. 7). There can be combinationsof projections attaching to the same or different fluid-activatedvoltaic cells, which can in turn be attached to one or more transmissionunits. A plurality of projections 200 A, B, C, D and E included on asingle appurtenance can be of varying shapes, sizes, and widths. Aplurality of projections 200 A, B, C, D and E included on a singleappurtenance can be configured to allow fluid flow through theprojections at different rates, for example with conduits of differentinternal dimensions.

A configuration of projections including projections of varying lengths,varying positional spacing, and extending at different angles can beconfigured to sample different regions of a wound dressing. Variousconfigurations can be utilized for particular medical monitoringrequirements. For example, one or more projections can be configured toextend into a region of the wound dressing adjacent to a periwoundregion to monitor fluid in that region of the dressing. A caregiver maywish to maintain low moisture content in the region of the wounddressing adjacent to the periwound region, for example to minimizemaceration and associated tissue damage. In such a situation, anappurtenance with multiple projections of a size and shape to extendinto the region of the specific wound dressing adjacent to the periwoundregion for a particular patient can be selected. If fluid becomesabundant in the region of the wound dressing adjacent to the periwoundregion, the fluid will flow through the projection and act as anelectrolyte in an attached fluid-activated voltaic cell. The resultingcurrent will activate a transmission unit attached to the attachedfluid-activated voltaic cell, resulting in a signal transmission andsubsequent notification of a caregiver that the wound dressing should bemanually checked. For example, an appurtenance with a plurality ofprojections of different discrete lengths can be utilized to samplefluid potentially present at different horizontal levels of a wounddressing. A caregiver may wish to be notified sequentially of the levelof fluid present in a particular deep dressing, for example if a woundbleeds through the entire depth of the dressing over time. Anappurtenance with a plurality of projections of different discretelengths can be utilized to monitor fluid potentially present in thedifferent layers, and to utilize current generated from a plurality offluid-activated voltaic cells to power one or more transmission unitsover time. Information from the resulting series of signals (e.g. timeof receipt, time between signals, elapsed time from wound dressingapplication) can be stored in memory at a remote unit for processing andnotification of a caregiver. For more general monitoring of fluidpresence in a wound dressing, an appurtenance with a plurality ofprojections spaced apart on the appurtenance, the projections ofdifferent lengths and extending at different angles (e.g. as illustratedin FIG. 12) can be employed to monitor a majority of the interior regionof the wound dressing.

FIG. 13 illustrates aspects of a system including a wound dressing withan affixed appurtenance combination unit 125. As shown in FIG. 12, awound dressing with an affixed appurtenance combination unit 125 isplaced over a wound on a body part 110 of a patient. For example, thebody part 110 can have been subject to a surgery, and therefore to havean acute wound. For example, the body part 110 can include an ulcer, andtherefore have a chronic wound. The wound dressing with an affixedappurtenance combination unit 125 transmits signals 1340 to the localunit 1310. The wound dressing with an affixed appurtenance combinationunit 125 is configured to transmit signals 1340 in response to anelectrochemical reaction generating a current within a fluid-activatedvoltaic cell of the appurtenance.

A local unit 1310 can include a handheld device. For example, the localunit 1310 can include a distinct handheld device. For example, the localunit 1310 can be included as part of a larger handheld unit, for examplea computing tablet, a laptop, a cell phone, a personal communicationdevice, or similar types of devices. A local unit 1310 can be configuredto be attached to a location, such as the end of a hospital bed, amedical stand, a bedside table, a wheelchair, or similar device. A localunit 1310 can be configured to be integrated into a piece of mobileequipment, such as the end of a hospital bed, a medical stand, awheelchair, or similar device. For example, a local unit can beintegrated with a medical cart, as described in U.S. Pat. No. 7,667,606to Packert et al., titled “RF Enabled Surgical Cart and Use of Same inOperating Room Environment,” which is incorporated herein by reference.A local unit 1310 can be configured to be integrated into a furnishing.For example, a local unit 1310 can be integrated into a hospital bed, abedside hospital monitor, a bedside table, a medical chair, a medicaltable, or similar furnishing. A local unit 1310 can include a displayunit 1320. In some embodiments, there can be a secondary deviceconfigured to relay signals from a wound dressing with an affixedappurtenance combination unit 125 to the local unit 1310, for example asdescribed in U.S. Pat. No. 7,986,235 to Posamentier titled “RFIDReceive-Only System,” which is incorporated herein by reference. Forexample, a secondary device configured to relay signals from a wounddressing with an affixed appurtenance combination unit 125 to the localunit 1310 can be configured to increase the signal strength to a localunit 1310 positioned a distance away from the wound dressing with anaffixed appurtenance combination unit 125. For example, a secondarydevice configured to relay signals from a wound dressing with an affixedappurtenance combination unit 125 to the local unit 1310 can beconfigured to relay signals from a plurality of wound dressings withaffixed appurtenance units 125 to a single local unit 1310. A local unit1310 can include an input device 1330, for example a keyboard. Althoughthe local unit 1310 illustrated in FIG. 13 includes a keyboard as aninput device 1330, in some embodiments the input device 1330 can includeother types of input devices, for example a touchscreen, stylus, keypad,or voice recognition system. The local unit 1310 can include memory,including memory configured to store information relating to signalsreceived from one or more combination units 125. Although notillustrated in FIG. 13, a local unit 1310 can transmit signals to acentral assembly, such as through wireless or a wired connection. A user1300, such as a medical caregiver, operates the local unit 1310.

A user 1300 can include a medical caregiver, such as a nurse or doctor,or a patient or other individual monitoring the wound dressing. Althoughuser 1300 is shown/described herein as a single illustrated figure,those skilled in the art will appreciate that user 1300 can berepresentative of a human user, a robotic user (e.g., computationalentity), and/or substantially any combination thereof (e.g., a user canbe assisted by one or more robotic agents) unless context dictatesotherwise. Those skilled in the art will appreciate that, in general,the same can be said of “sender” and/or other entity-oriented terms assuch terms are used herein unless context dictates otherwise. A user1300 can utilize a local unit 1310 through a user interface, for exampleone or more buttons, a keyboard, a touchscreen, a voice recognitiondevice, a stylus, or other means.

A local unit 1310 can be configured to monitor for signals to one ormore wound dressings with attached appurtenances 125 automatically. Thesignals 1340 sent from the wound dressing with attached appurtenanceunit 125 to the local unit 1310 can be radio frequency signals in aparticular wavelength, or range of wavelengths. For example, the signalscan be in the UHF range, such as a UHF sub-range commonly used in aparticular geographic region. See, for example the “Worldwide RFID UHFMap” by Intelleflex Corporation (©2009), which is incorporated herein byreference. For example, the signals can be in a range specified by anindustry standard. For example, the signals can be in the approximately13.56 megahertz (MHz) range, or within the ISO 14443 standardparameters. For example, the signals can be in the IEEE 802.11x standardor the Bluetooth standard range. See, for example, U.S. Pat. No.7,215,976 to Brideglall, titled “RFID Device, System and Method ofOperation Including a Hybrid backscatter-based RFID Protocol Compatiblewith RFID, Bluetooth and/or IEEE 802.11x Infrastructure,” which isincorporated herein by reference. For example, the signals can be in theapproximately 131 kilohertz (KHz) range, for example as part of a RuBee™(IEEE standard 1902.1) system (i.e. equipment sold by Visible Assets™,Inc.). See for example: the description of RuBee™ systems from theVisible Assets™ webpage; Stevens et al., “RuBee (IEEE 1902.1)—ThePhysics Behind, Real-Time, High Security Wireless Asset VisibilityNetworks in Harsh Environments,” a white paper from Visible Assets™; andin US Patent Application No. 2007/0171076 to Stevens and Waterhouse,titled “Low-frequency Radio Tag Encapsulating System,” each of which areincorporated herein by reference.

In some embodiments, the wound dressing with attached appurtenance unit125 includes a backscatter or reflective transmission device, and so thesignals 1340 sent from the wound dressing with attached appurtenanceunit 125 to the local unit 1310 can include backscatter or reflectivesignals. For example, as described in “Fundamental OperatingPrinciples,” in Chapter 3 of the RFID Handbook: Fundamentals andApplications in Contactless Smart Cards and Identification, KlausFinkenzeller, John Wiley & Sons, (2003), which is incorporated herein byreference.

The signals 1340 transmitted from the wound dressing with attachedappurtenance combination unit 125 can be sent in a fixed direction fromthe transmission source. The wound dressing with attached appurtenancecombination unit 125 and the local unit 1310 can each include markingsor other visible aspects directing a user how as to orient the wounddressing with attached appurtenance combination unit 125 and the localunit 1310 relative to each other for signal directionality.

In many embodiments, it is envisioned that the signal strength of asignal 1340 transmitted from the wound dressing with attachedappurtenance combination unit 125 will be such that the signal 1340 willnot travel a significant distance. The local unit 1310 and the wounddressing with attached appurtenance combination unit 125 can, therefore,need to be placed in reasonably close proximity for signals 1340 totravel between the devices. For example, the signal 1340 transmittedfrom the wound dressing with attached appurtenance combination unit 125can be such that the receiver of such signals should be within the sameroom. For example, the signal 1340 transmitted from the wound dressingwith attached appurtenance combination unit 125 can be such that thereceiver of such signals should be within 10 feet. For example, thesignal 1340 transmitted from the wound dressing with attachedappurtenance combination unit 125 can be such that the receiver of suchsignals should be within 3 feet.

FIG. 14 illustrates aspects of a local unit 1310. As shown in FIG. 14, alocal unit 1310 includes a display unit 1320 and a input device 1330. Auser 1320 operates the local unit 1310. The local unit 1310 includescircuitry for accepting a signal from an appurtenance attached to awound dressing 1400. The local unit 1310 includes circuitry forprocessing a signal from an appurtenance attached to a wound dressing1410.

In some embodiments, an appurtenance to a wound dressing includes anappurtenance configured to attach to a wound dressing, the appurtenanceincluding a conduit configured to allow fluid flow from an interiorregion of a wound dressing into the appurtenance; a fluid-activatedvoltaic cell including an internal chamber, the internal chamberattached to the conduit; and a radio frequency identification (RFID)unit attached to the fluid-activated voltaic cell and configured tooperate in response to current generated by the fluid-activated voltaiccell. The internal chamber can be configured to receive the fluidflowing through the conduit. The conduit can include a plurality ofmicrochannels configured to direct fluid flow into the fluid-activatedvoltaic cell. See, for example, U.S. Pat. No. 6,420,622 to Johnston,“Medical Article Having Fluid Control Film,” which is incorporated byreference herein. The RFID unit can include a unique identifier for thatunit. The RFID unit can include an antenna, and circuitry configured toinitiate signal transmission from the antenna. The RFID unit can includea processor. Some embodiments also include a second conduit positionedto allow fluid flow from a second interior region of a wound dressinginto the appurtenance; and a second fluid-activated voltaic cellincluding an internal chamber, the internal chamber attached to thesecond conduit, wherein the second fluid-activated voltaic cell isconfigured to direct current to the RFID unit. Some embodiments alsoinclude a sensor attached to the conduit; and a connector between thesensor and the RFID unit.

A method of monitoring a wound includes the steps of: conveying fluidfrom an interior region of a wound dressing to an appurtenance of thewound dressing; placing the fluid adjacent to a first electrode and asecond electrode of a fluid-activated voltaic cell integral to theappurtenance; and utilizing current received from the fluid-activatedvoltaic cell directly to send a wireless signal beyond the appurtenance.For example, a transmission unit connected to the fluid-activatedvoltaic cell integral to the appurtenance can send a wireless signalbeyond the appurtenance in response to the current generated by thefluid-activated voltaic cell.

The state of the art has progressed to the point where there is littledistinction left between hardware, software, and/or firmwareimplementations of aspects of systems; the use of hardware, software,and/or firmware is generally (but not always, in that in certaincontexts the choice between hardware and software can becomesignificant) a design choice representing cost vs. efficiency tradeoffs.There are various vehicles by which processes and/or systems and/orother technologies described herein can be effected (e.g., hardware,software, and/or firmware), and that the preferred vehicle will varywith the context in which the processes and/or systems and/or othertechnologies are deployed. For example, if an implementer determinesthat speed and accuracy are paramount, the implementer can opt for amainly hardware and/or firmware vehicle; alternatively, if flexibilityis paramount, the implementer can opt for a mainly softwareimplementation; or, yet again alternatively, the implementer can opt forsome combination of hardware, software, and/or firmware. Hence, thereare several possible vehicles by which the processes and/or devicesand/or other technologies described herein can be effected, none ofwhich is inherently superior to the other in that any vehicle to beutilized is a choice dependent upon the context in which the vehiclewill be deployed and the specific concerns (e.g., speed, flexibility, orpredictability) of the implementer, any of which can vary. Opticalaspects of implementations will typically employ optically-orientedhardware, software, and or firmware.

In some implementations described herein, logic and similarimplementations can include software or other control structures.Electronic circuitry, for example, can have one or more paths ofelectrical current constructed and arranged to implement variousfunctions as described herein. In some implementations, one or moremedia can be configured to bear a device-detectable implementation whensuch media hold or transmit a device detectable instructions operable toperform as described herein. In some variants, for example,implementations can include an update or modification of existingsoftware or firmware, or of gate arrays or programmable hardware, suchas by performing a reception of or a transmission of one or moreinstructions in relation to one or more operations described herein.Alternatively or additionally, in some variants, an implementation caninclude special-purpose hardware, software, firmware components, and/orgeneral-purpose components executing or otherwise invokingspecial-purpose components. Specifications or other implementations canbe transmitted by one or more instances of tangible transmission mediaas described herein, optionally by packet transmission or otherwise bypassing through distributed media at various times.

Alternatively or additionally, implementations can include executing aspecial-purpose instruction sequence or invoking circuitry for enabling,triggering, coordinating, requesting, or otherwise causing one or moreoccurrences of virtually any functional operations described herein. Insome variants, operational or other logical descriptions herein can beexpressed as source code and compiled or otherwise invoked as anexecutable instruction sequence. In some contexts, for example,implementations can be provided, in whole or in part, by source code,such as C++, or other code sequences. In other implementations, sourceor other code implementation, using commercially available and/ortechniques in the art, can be compiled//implemented/translated/convertedinto a high-level descriptor language (e.g., initially implementingdescribed technologies in C or C++ programming language and thereafterconverting the programming language implementation into alogic-synthesizable language implementation, a hardware descriptionlanguage implementation, a hardware design simulation implementation,and/or other such similar mode(s) of expression). For example, some orall of a logical expression (e.g., computer programming languageimplementation) can be manifested as a Verilog-type hardware description(e.g., via Hardware Description Language (HDL) and/or Very High SpeedIntegrated Circuit Hardware Descriptor Language (VHDL)) or othercircuitry model which can then be used to create a physicalimplementation having hardware (e.g., an Application Specific IntegratedCircuit). Those skilled in the art will recognize how to obtain,configure, and optimize suitable transmission or computational elements,material supplies, actuators, or other structures in light of theseteachings.

The foregoing detailed description has set forth various embodiments ofthe devices and/or processes via the use of block diagrams, flowcharts,and/or examples. Insofar as such block diagrams, flowcharts, and/orexamples contain one or more functions and/or operations, each functionand/or operation within such block diagrams, flowcharts, or examples canbe implemented, individually and/or collectively, by a wide range ofhardware, software, firmware, or virtually any combination thereof. Inone embodiment, several portions of the subject matter described hereincan be implemented via Application Specific Integrated Circuits (ASICs),Field Programmable Gate Arrays (FPGAs), digital signal processors(DSPs), or other integrated formats. However, some aspects of theembodiments disclosed herein, in whole or in part, can be equivalentlyimplemented in integrated circuits, as one or more computer programsrunning on one or more computers (e.g., as one or more programs runningon one or more computer systems), as one or more programs running on oneor more processors (e.g., as one or more programs running on one or moremicroprocessors), as firmware, or as virtually any combination thereof,and that designing the circuitry and/or writing the code for thesoftware and or firmware would be well within the skill of one of skillin the art in light of this disclosure. In addition, the mechanisms ofthe subject matter described herein are capable of being distributed asa program product in a variety of forms, and that an illustrativeembodiment of the subject matter described herein applies regardless ofthe particular type of signal bearing medium used to actually carry outthe distribution. Examples of a signal bearing medium include, but arenot limited to, the following: a recordable type medium such as a floppydisk, a hard disk drive, a Compact Disc (CD), a Digital Video Disk(DVD), a digital tape, a computer memory, etc.; and a transmission typemedium such as a digital and/or an analog communication medium (e.g., afiber optic cable, a waveguide, a wired communications link, a wirelesscommunication link (e.g., transmitter, receiver, transmission logic,reception logic, etc.), etc.).

In a general sense, the various embodiments described herein can beimplemented, individually and/or collectively, by various types ofelectro-mechanical systems having a wide range of electrical componentssuch as hardware, software, firmware, and/or virtually any combinationthereof; and a wide range of components that can impart mechanical forceor motion such as rigid bodies, spring or torsional bodies, hydraulics,electro-magnetically actuated devices, and/or virtually any combinationthereof. Consequently, as used herein “electro-mechanical system”includes, but is not limited to, electrical circuitry operably coupledwith a transducer (e.g., an actuator, a motor, a piezoelectric crystal,a Micro Electro Mechanical System (MEMS), etc.), electrical circuitryhaving at least one discrete electrical circuit, electrical circuitryhaving at least one integrated circuit, electrical circuitry having atleast one application specific integrated circuit, electrical circuitryforming a general purpose computing device configured by a computerprogram (e.g., a general purpose computer configured by a computerprogram which at least partially carries out processes and/or devicesdescribed herein, or a microprocessor configured by a computer programwhich at least partially carries out processes and/or devices describedherein), electrical circuitry forming a memory device (e.g., forms ofmemory (e.g., random access, flash, read only, etc.)), electricalcircuitry forming a communications device (e.g., a modem, communicationsswitch, optical-electrical equipment, etc.), and/or any non-electricalanalog thereto, such as optical or other analogs. Examples ofelectro-mechanical systems include but are not limited to a variety ofconsumer electronics systems, medical devices, as well as other systemssuch as motorized transport systems, factory automation systems,security systems, and/or communication/computing systems.Electro-mechanical as used herein is not necessarily limited to a systemthat has both electrical and mechanical actuation except as context candictate otherwise.

In a general sense, the various aspects described herein can beimplemented, individually and/or collectively, by a wide range ofhardware, software, firmware, and/or any combination thereof and can beviewed as being composed of various types of “electrical circuitry.”Consequently, as used herein “electrical circuitry” includes, but is notlimited to, electrical circuitry having at least one discrete electricalcircuit, electrical circuitry having at least one integrated circuit,electrical circuitry having at least one application specific integratedcircuit, electrical circuitry forming a general purpose computing deviceconfigured by a computer program (e.g., a general purpose computerconfigured by a computer program which at least partially carries outprocesses and/or devices described herein, or a microprocessorconfigured by a computer program which at least partially carries outprocesses and/or devices described herein), electrical circuitry forminga memory device (e.g., forms of memory (e.g., random access, flash, readonly, etc.)), and/or electrical circuitry forming a communicationsdevice (e.g., a modem, communications switch, optical-electricalequipment, etc.). The subject matter described herein can be implementedin an analog or digital fashion or some combination thereof. At least aportion of the devices and/or processes described herein can beintegrated into an image processing system. A typical image processingsystem generally includes one or more of a system unit housing, a videodisplay device, memory such as volatile or non-volatile memory,processors such as microprocessors or digital signal processors,computational entities such as operating systems, drivers, applicationsprograms, one or more interaction devices (e.g., a touch pad, a touchscreen, an antenna, etc.), control systems including feedback loops andcontrol motors (e.g., feedback for sensing lens position and/orvelocity; control motors for moving/distorting lenses to give desiredfocuses). An image processing system can be implemented utilizingsuitable commercially available components, such as those typicallyfound in digital still systems and/or digital motion systems.

At least a portion of the devices and/or processes described herein canbe integrated into a data processing system. A data processing systemgenerally includes one or more of a system unit housing, a video displaydevice, memory such as volatile or non-volatile memory, processors suchas microprocessors or digital signal processors, computational entitiessuch as operating systems, drivers, graphical user interfaces, andapplications programs, one or more interaction devices (e.g., a touchpad, a touch screen, an antenna, etc.), and/or control systems includingfeedback loops and control motors (e.g., feedback for sensing positionand/or velocity; control motors for moving and/or adjusting componentsand/or quantities). A data processing system can be implementedutilizing suitable commercially available components, such as thosetypically found in data computing/communication and/or networkcomputing/communication systems.

The herein described components (e.g., operations), devices, objects,and the discussion accompanying them are used as examples for the sakeof conceptual clarity and that various configuration modifications arecontemplated. Consequently, as used herein, the specific examples setforth and the accompanying discussion are intended to be representativeof their more general classes. In general, use of any specific exampleis intended to be representative of its class, and the non-inclusion ofspecific components (e.g., operations), devices, and objects should notbe taken limiting.

The herein described subject matter sometimes illustrates differentcomponents contained within, or connected with, different othercomponents. It is to be understood that such depicted architectures aremerely examples, and that in fact many other architectures can beimplemented which achieve the same functionality. In a conceptual sense,any arrangement of components to achieve the same functionality iseffectively “associated” such that the desired functionality isachieved. Hence, any two components herein combined to achieve aparticular functionality can be seen as “associated with” each othersuch that the desired functionality is achieved, irrespective ofarchitectures or intermedial components. Likewise, any two components soassociated can also be viewed as being “operably connected,” or“operably coupled,” to each other to achieve the desired functionality,and any two components capable of being so associated can also be viewedas being “operably couplable,” to each other to achieve the desiredfunctionality. Specific examples of operably couplable include but arenot limited to physically mateable and/or physically interactingcomponents, and/or wirelessly interactable, and/or wirelesslyinteracting components, and/or logically interacting, and/or logicallyinteractable components.

With respect to the use of substantially any plural and/or singularterms herein, the plural can be translated to the singular and/or fromthe singular to the plural as is appropriate to the context and/orapplication. The various singular/plural permutations are not expresslyset forth herein for sake of clarity.

In some instances, one or more components can be referred to herein as“configured to,” “configured by,” “configurable to,” “operable/operativeto,” “adapted/adaptable,” “able to,” “conformable/conformed to,” etc.Those skilled in the art will recognize that such terms (e.g.“configured to”) can generally encompass active-state components and/orinactive-state components and/or standby-state components, unlesscontext requires otherwise.

While particular aspects of the present subject matter described hereinhave been shown and described, changes and modifications can be madewithout departing from the subject matter described herein and itsbroader aspects and, therefore, the appended claims are to encompasswithin their scope all such changes and modifications as are within thetrue spirit and scope of the subject matter described herein. Terms usedherein, and especially in the appended claims (e.g., bodies of theappended claims) are generally intended as “open” terms (e.g., the term“including” should be interpreted as “including but not limited to,” theterm “having” should be interpreted as “having at least,” the term“includes” should be interpreted as “includes but is not limited to,”etc.). If a specific number of an introduced claim recitation isintended, such an intent will be explicitly recited in the claim, and inthe absence of such recitation no such intent is present. For example,as an aid to understanding, the following appended claims can containusage of the introductory phrases “at least one” and “one or more” tointroduce claim recitations. However, the use of such phrases should notbe construed to imply that the introduction of a claim recitation by theindefinite articles “a” or “an” limits any particular claim containingsuch introduced claim recitation to claims containing only one suchrecitation, even when the same claim includes the introductory phrases“one or more” or “at least one” and indefinite articles such as “a” or“an” (e.g., “a” and/or “an” should typically be interpreted to mean “atleast one” or “one or more”); the same holds true for the use ofdefinite articles used to introduce claim recitations. In addition, evenif a specific number of an introduced claim recitation is explicitlyrecited, such recitation should typically be interpreted to mean atleast the recited number (e.g., the bare recitation of “tworecitations,” without other modifiers, typically means at least tworecitations, or two or more recitations). Furthermore, in thoseinstances where a convention analogous to “at least one of A, B, and C,etc.” is used, in general such a construction is intended in the senseone having skill in the art would understand the convention (e.g., “asystem having at least one of A, B, and C” would include but not belimited to systems that have A alone, B alone, C alone, A and Btogether, A and C together, B and C together, and/or A, B, and Ctogether, etc.). In those instances where a convention analogous to “atleast one of A, B, or C, etc.” is used, in general such a constructionis intended in the sense one having skill in the art would understandthe convention (e.g., “a system having at least one of A, B, or C” wouldinclude but not be limited to systems that have A alone, B alone, Calone, A and B together, A and C together, B and C together, and/or A,B, and C together, etc.). Typically a disjunctive word and/or phrasepresenting two or more alternative terms, whether in the description,claims, or drawings, should be understood to contemplate thepossibilities of including one of the terms, either of the terms, orboth terms unless context dictates otherwise. For example, the phrase “Aor B” will be typically understood to include the possibilities of “A”or “B” or “A and B.”

With respect to the appended claims, the recited operations therein cangenerally be performed in any order. Also, although various operationalflows are presented in a sequence(s), it should be understood that thevarious operations can be performed in other orders than those which areillustrated, or can be performed concurrently. Examples of suchalternate orderings can include overlapping, interleaved, interrupted,reordered, incremental, preparatory, supplemental, simultaneous,reverse, or other variant orderings, unless context dictates otherwise.Furthermore, terms like “responsive to,” “related to,” or otherpast-tense adjectives are generally not intended to exclude suchvariants, unless context dictates otherwise.

Example An Appurtenance to a Wound Dressing Configured with a FluidActivated Voltaic Cell to Detect and Report Fluid in a Wound Dressing inReal Time

An appurtenance to a wound dressing is constructed from a flexible thinplastic substrate that is configured in a substantially planar shape(see FIG. 5). The appurtenance contains a transmission unit thatincludes: a microprocessor, memory, a transmitter, and an RFID antenna.The components are attached to a surface of the substrate with epoxy;and circuitry for the RFID are attached to the substrate with adhesiveand connected to the antenna with conductive ink (e.g., polymer withflecks of silver) to create an operational RFID. A fluid activatedvoltaic cell is attached to the substrate and connected to the RFID witha wire connection. An aperture for a polyester tube with approximately0.5 mm inside diameter is mounted in contact with the fluid activatedvoltaic cell (see FIG. 5) and attached to a polyester tube that projectsaway from the surface of the substrate for approximately 4 millimeters(mm). Encapsulating epoxy material is used to cover the components, theRFID circuitry, the conductive ink, conductive epoxy, the fluidactivated voltaic cell and exterior of the tube port. A space ismaintained around the edge of the polyester tube adjacent to the fluidactivated voltaic cell under the encapsulating epoxy material. The spaceis configured to allow fluid to flow from the tube into contact with thefluid activated voltaic cell. The space is approximately 1 mm high andof sufficient lateral dimensions to cover the electrodes of the fluidactivated voltaic cell (approximately 12 mm×12 mm).

Methods and circuitry to construct passive RFID tags are described (seee.g., U.S. Pat. No. 7,479,886 issued to Burr, “Antenna Capacitance forEnergy Storage” and Chawla, “An Overview of Passive RFID,” IEEEApplications & Practice, 11-17, (September 2007), which are eachincorporated herein by reference). For example, the device can contain adipole antenna of 22-gauge copper magnet wire, a rectifier to convertincoming UHF energy into DC, a capacitor to store the energy, and aprogrammable microcontroller (e.g., a MSP430™ microcontroller availablefrom Texas Instruments, Dallas, Tex.) to perform sensing and computation(see e.g., Sample et al., “Design of an RFID-Based Battery-FreeProgrammable Sensing Platform,” IEEE Trans. Instr. Meas. 57: 2608-2615,2008 which is incorporated herein by reference). The RFID device canharvest energy from incoming radio waves or be empowered by currentgenerated by the fluid activated voltaic cell.

A fluid activated voltaic cell serves as a moisture sensor and generateselectrical current to empower the RFID device. A fluid activated voltaiccell is micro-fabricated from a silicon wafer with metallic layersserving as electrodes and wound fluids (e.g., exudate and blood)providing electrolyte to activate the voltaic cell. For example, a fluidactivated voltaic cell can be constructed with magnesium, Mg, as theanode and silver chloride, AgCl, as the cathode (see e.g., Sammoura etal., Sensors and Actuators A 111: 79-86, 2004 and Lee et al., “WaterActivated Disposable and Long Shelf Life Microbatteries,” Proceedings ofIEEE Micro Electro Mechanical Systems Conference, pp. 387-390, Kyoto,Japan, January 2003 which are incorporated herein by reference). A fluidactivated voltaic cell is fabricated from silicon wafers by depositing alayer of Mg on a top substrate and AgCl on a bottom substrate andcreating a gap of approximately 50 μm between the Mg and AgCl layersusing spacers. A layer of chromium/gold is deposited under the AgCllayer to collect electrons from the voltaic cell. A voltaic cellapproximately 12 mm×12 mm produces a maximum output voltage ofapproximately 1.65 Volts with a voltaic cell capacity of approximately1.8 mWatt-hours when the cell is activated with a drop of water,approximately 40 μL, and discharged under a resistance of 1 kilohm. Thiscorresponds to reaching a maximum voltage of 1.6 V within a minute ofactivation and maintaining this level for approximately 20 minutesfollowed by a gradual decline to 0.6 V over the next 40 minutes. Theoutput voltage of the fluid activated cell may be increased by providingenhancers that promote the electromotive force of the cell. For example,an enhancer of desiccated acid can be included in the electrochemicalcell to produce acidic fluid and increase the voltage produced by thecell when fluid enters the cell (see e.g., Goodisman, “Observation onLemon Cells”, J. Chem. Ed. 78: 516-518, 2001 which is incorporatedherein by reference). The provision of solid citric acid as an enhancerwhich dissolves upon contact with wound fluids can lower the pH of thefluid within the cell to approximately 3.0 and increase theelectromotive force of the cell by increasing the dissolution of Mg (seee.g., Goodisman, Ibid.).

The substrate of the appurtenance is attached to the outer surface of awound dressing with adhesive. A styrene copolymer pressure-sensitiveadhesive can be used. In addition, the distal end of the polyester tubeis pressed into the layers of the wound dressing with finger-tippressure. The wound dressing is of sufficient thickness so as tomaintain the end of the polyester tube within the layers of the wounddressing, allowing for both the length of the tube itself and the angleit projects from the substrate. For example, if the tube is 4 mm long,the wound dressing can be 6 mm thick, or greater. For example, if thetube is 4 mm long, the wound dressing can be 4 mm thick if the tube isplaced at a sufficient angle to maintain the distal end of the tubewithin the wound dressing. The wound dressing with the appurtenance isplaced immediately over the wound and the RFID identity number, patientinformation, the time and date are entered into a central computersystem after interrogating the RFID tag with a RFID reader in a localunit and accessing the patient's electronic medical record. If thepatient is wearing an RFID identification device (such as a wristbandwith an embedded RFID unit) the patient information can be input intothe system by scanning the identification device in association withscanning the appurtenance.

The fluid activated voltaic cell is in fluid communication with thelower portion of the appurtenance relative to the insertion point intothe wound dressing. For example, the voltaic cell is located adjacent toan opening in the enclosure and is used to monitor the amount of fluidsthat emanate from the wound and flow through the projection tube bycapillary action. Wound moisture levels are correlated with healing, anda rapid increase in moisture level can indicate a microbial infection ispresent (see e.g., U.S. Pat. No. 6,963,772 to Bloom et al.,“User-Retainable Temperature and Impedance Monitoring Methods andDevices,” which is incorporated herein by reference). Wound fluidentering the aperture activates the fluid activated voltaic cell whichcan yield approximately 1.8 mW-hours power (see e.g., Sammoura et al.,Ibid.) to empower the RFID device which can operate with approximately600 μW of power (see e.g., Sample et al., Ibid.). The empowered RFIDdevice transmits a UHF signal which is received by a local unit proximalto the patient.

A RFID reader in a local unit (for example, a cell phone) proximal tothe patient (e.g., on the edge of the patient's hospital bed or on abedside table) receives the UHF signal from the RFID device. The UHFsignal encodes information such as the patient's identity, the patient'sroom number, the identification number and location of the appurtenance,and the day and time of the signal transmission. The local unit respondsby transmitting signals at the bedside to alert the patient and to acentral computer to notify healthcare personnel. For example the localunit can signal at the bedside by emitting an audible alarm, andtransmit wirelessly to a central computer which can notify caregivers,for example, through a message sent to the nursing station. The localunit can also indicate to a healthcare worker the need to change a wounddressing based on the elapsed time since the wound dressing was applied(i.e. when the appurtenance was first “read” into the system). Moreoverthe local unit transmission to a central computer creates a record inthe patient's electronic health record which includes all of theinformation transmitted by the local unit relating to that appurtenanceand any other appurtenances utilized by the same patient over time.

All of the above U.S. patents, U.S. patent application publications,U.S. patent applications, foreign patents, foreign patent applicationsand non-patent publications referred to in this specification and/orlisted in any Application Data Sheet, are incorporated herein byreference, to the extent not inconsistent herewith.

While various aspects and embodiments have been disclosed herein, otheraspects and embodiments will be apparent to those skilled in the art.The various aspects and embodiments disclosed herein are for purposes ofillustration and are not intended to be limiting, with the true scopeand spirit being indicated by the following claims.

What is claimed is:
 1. An appurtenance to a wound dressing, comprising:a substrate configured to attach to a wound dressing; a fluid-activatedvoltaic cell attached to the substrate; a transmission unit attached toa surface of the substrate, the transmission unit including circuitryand at least one antenna, the transmission unit configured to transmit asignal in response to the fluid-activated voltaic cell; and a projectionoperably attached to the fluid-activated voltaic cell, the projection ofa size and shape to extend into an interior region of the wound dressingand configured to sample a fluid within the interior region of the wounddressing. 2.-5. (canceled)
 6. The appurtenance of claim 1, wherein thefluid-activated voltaic cell comprises: at least one enhancement unitconfigured to release at least one chemical enhancer of anelectrochemical reaction within the fluid-activated voltaic cell inresponse to contact with the fluid.
 7. The appurtenance of claim 6,wherein the at least one enhancement unit comprises: at least one dryacid unit configured to release an acid when contacted by a liquid.8.-10. (canceled)
 11. The appurtenance of claim 1, wherein thefluid-activated voltaic cell comprises: a chamber configured to receivethe fluid.
 12. The appurtenance of claim 1, wherein the transmissionunit comprises: a radio frequency identification (RFID) unit.
 13. Theappurtenance of claim 1, wherein the transmission unit comprises: a nearfield communication (NFC) unit.
 14. The appurtenance of claim 1, whereinthe transmission unit comprises: a unique identifier.
 15. (canceled) 16.The appurtenance of claim 1, wherein the transmission unit comprises: aprocessor.
 17. The appurtenance of claim 1, wherein the projectioncomprises: at least one substantially hollow tube with a first apertureat a location adjacent to the interior region of the wound dressing anda second aperture at a location adjacent to a surface of thefluid-activated voltaic cell.
 18. The appurtenance of claim 1, whereinthe projection comprises: a plurality of apertures located along alength of the projection; and a plurality of conduits, each conduitincluding a first end attached to one of the plurality of apertures, anda second end attached to the fluid-activated voltaic cell, each conduitconfigured to direct the fluid from the interior region of the wounddressing into the fluid-activated voltaic cell.
 19. The appurtenance ofclaim 1, wherein the projection is partially positioned within thefluid-activated voltaic cell, and wherein the projection includes anaperture within the fluid-activated voltaic cell.
 20. The appurtenanceof claim 1, comprising: a wire connector between the fluid-activatedvoltaic cell and the transmission unit.
 21. The appurtenance of claim 1,comprising: a passive radio frequency identification (RFID) unitincluding an identifier.
 22. The appurtenance of claim 1, comprising: asecond fluid-activated voltaic cell attached to the substrate andconfigured to activate the transmission unit; and a second projectionoperably attached to the second fluid-activated voltaic cell, the secondprojection configured to sample a second fluid within a second interiorregion of the wound dressing.
 23. The appurtenance of claim 1,comprising: a sensor connected to the transmission unit.
 24. Anappurtenance to a wound dressing, comprising: an enclosure of a heightand width to fit substantially within an interior region of a wounddressing, the enclosure including at least one aperture configured toallow a fluid to flow from the interior region of the wound dressinginto the enclosure; a fluid-activated voltaic cell attached to one ormore of the at least one aperture; and a transmission unit attached toan internal surface of the enclosure, the transmission unit includingcircuitry and at least one antenna, the transmission unit configured totransmit a signal in response to the fluid-activated voltaic cell. 25.The appurtenance of claim 24, wherein the enclosure comprises: asubstantially cylindrical structure, wherein a largest width of thesubstantially cylindrical structure is less than a smallest width of thewound dressing.
 26. The appurtenance of claim 24, wherein the enclosurecomprises: a substantially pyramidal structure, wherein a largest widthof the substantially pyramidal structure is less than a smallest widthof the wound dressing.
 27. (canceled)
 28. The appurtenance of claim 24,wherein the enclosure comprises: one or more walls, the walls forming aflange on an edge of the enclosure, the flange positioned to attach afastener between a surface of the wound dressing and the enclosure. 29.The appurtenance of claim 24, wherein the enclosure comprises: one ormore walls, the walls forming a flange on an edge of the enclosure, theflange including one or more projections from a surface of the flange,the one or more projections positioned to pierce an outer surface of thewound dressing.
 30. (canceled)
 31. The appurtenance of claim 24, whereinthe enclosure comprises: a substantially hollow tube.
 32. Theappurtenance of claim 24, wherein the enclosure comprises: a pluralityof apertures.
 33. The appurtenance of claim 24, wherein the at least oneaperture of the enclosure comprises: a micro-capillary film configuredto direct the fluid from the interior region of the wound dressing intoan interior of the enclosure.
 34. The appurtenance of claim 24, whereinthe at least one aperture of the enclosure comprises: a conduitconfigured to direct the fluid from the interior region of the wounddressing into an interior of the enclosure.
 35. The appurtenance ofclaim 24, wherein the fluid-activated voltaic cell comprises: at leastone enhancement unit configured to release at least one chemicalenhancer of an electrochemical reaction within the fluid-activatedvoltaic cell in response to contact with the fluid.
 36. The appurtenanceof claim 35, wherein the at least one enhancement unit comprises: atleast one dry acid unit configured to release acid when contacted by aliquid. 37.-39. (canceled)
 40. The appurtenance of claim 24, wherein thefluid-activated voltaic cell comprises: a chamber configured to receivethe fluid.
 41. The appurtenance of claim 24, wherein the transmissionunit comprises: a radio frequency identification (RFID) unit.
 42. Theappurtenance of claim 24, wherein the transmission unit comprises: anear filed communication (NFC) unit.
 43. The appurtenance of claim 24,wherein the transmission unit comprises: a unique identifier. 44.(canceled)
 45. The appurtenance of claim 24, wherein the transmissionunit comprises: a processor.
 46. The appurtenance of claim 24,comprising: a wire connector between the fluid-activated voltaic celland the transmission unit.
 47. The appurtenance of claim 24, comprising:a passive radio frequency identification (RFID) unit including anidentifier.
 48. The appurtenance of claim 24, comprising: a secondfluid-activated voltaic cell attached to at least one second aperture,the at least one second aperture configured to allow a fluid to flowfrom a second interior region of the wound dressing into an interior ofthe second fluid-activated voltaic cell.
 49. The appurtenance of claim24, comprising: a sensor attached to the at least one aperture of theenclosure; and a connection between the sensor and the transmissionunit.
 50. An appurtenance to a wound dressing, comprising: anappurtenance configured to attach to a wound dressing, the appurtenanceincluding a conduit configured to allow a fluid to flow from an interiorregion of the wound dressing into the appurtenance; a fluid-activatedvoltaic cell including an internal chamber, the internal chamberattached to the conduit; and a radio frequency identification (RFID)unit attached to the fluid-activated voltaic cell and configured tooperate in response to electrical power generated by the fluid-activatedvoltaic cell. 51.-52. (canceled)
 53. The appurtenance of claim 50,wherein the appurtenance is configured to attach to an exterior surfaceof the wound dressing.
 54. The appurtenance of claim 50, wherein theconduit comprises: a plurality of microchannels configured to direct thefluid to flow into the fluid-activated voltaic cell.
 55. Theappurtenance of claim 50, wherein the conduit comprises: at least oneprojection, the projection including at least one aperture positioneddistal to the appurtenance, the projection configured to allow the fluidto flow from the interior region of the wound dressing into theappurtenance.
 56. The appurtenance of claim 50, wherein thefluid-activated voltaic cell comprises: at least one enhancement unitconfigured to release at least one chemical enhancer of anelectrochemical reaction within the fluid-activated voltaic cell inresponse to contact with the fluid.
 57. The appurtenance of claim 56,wherein the at least one enhancement unit comprises: at least one dryacid unit configured to release an acid when contacted by a liquid.58.-60. (canceled)
 61. The appurtenance of claim 50, wherein thefluid-activated voltaic cell comprises: a chamber attached to theconduit, the chamber configured to receive the fluid.
 62. Theappurtenance of claim 50, wherein the radio frequency identification(RFID) unit comprises: a unique identifier.
 63. The appurtenance ofclaim 50, wherein the radio frequency identification (RFID) unitcomprises: an antenna; and circuitry configured to initiate a signaltransmission from the antenna.
 64. The appurtenance of claim 50, whereinthe radio frequency identification (RFID) unit comprises: a processor.65. (canceled)
 66. The appurtenance of claim 50, comprising: a secondconduit positioned to allow the fluid to flow from a second interiorregion of the wound dressing into the appurtenance; and a secondfluid-activated voltaic cell including a second internal chamber, thesecond internal chamber attached to the second conduit, wherein thesecond fluid-activated voltaic cell is configured to direct current tothe radio frequency identification (RFID) unit.
 67. The appurtenance ofclaim 50, comprising: a sensor attached to the conduit; and a connectorbetween the sensor and the radio frequency identification (RFID) unit.68. (canceled)